[PATCH V6 00/15] Add support for stacked/parallel memories

[PATCH V6 00/15] Add support for stacked/parallel memories

[Amit Kumar Mahapatra]

This patch is in the continuation to the discussions which happened on
'commit f89504300e94 ("spi: Stacked/parallel memories bindings")' for
adding dt-binding support for stacked/parallel memories.

This patch series updated the spi-nor, spi core and the spi drivers
to add stacked and parallel memories support.

The first patch
https://lore.kernel.org/all/20230119185342.2093323-1-amit.kumar-mahapatra@amd.com/
of the previous series got applied to
https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git for-next
But the rest of the patches in the series did not get applied due to merge
conflict, so send the remaining patches in the series after rebasing it
on top of for-next branch.
---
BRANCH: for-next

Changes in v6:
- Rebased on top of latest v6.3-rc1 and fixed merge conflicts in
  spi-mpc512x-psc.c, sfdp.c, spansion.c files and removed spi-omap-100k.c.
- Updated spi_dev_check( ) to reject new devices if any one of the
  chipselect is used by another device.

Changes in v5:
- Rebased the patches on top of v6.3-rc1 and fixed the merge conflicts.
- Fixed compilation warnings in spi-sh-msiof.c with shmobile_defconfig  

Changes in v4:
- Fixed build error in spi-pl022.c file - reported by Mark.
- Fixed build error in spi-sn-f-ospi.c file.
- Added Reviewed-by: Serge Semin <fancer.lancer@gmail.com> tag.
- Added two more patches to replace spi->chip_select with API calls in
  mpc832x_rdb.c & cs35l41_hda_spi.c files.

Changes in v3:
- Rebased the patches on top of
  https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git for-next
- Added a patch to convert spi_nor_otp_region_len(nor) &
  spi_nor_otp_n_regions(nor) macros into inline functions
- Added Reviewed-by & Acked-by tags

Changes in v2:
- Rebased the patches on top of v6.2-rc1
- Created separate patch to add get & set APIs for spi->chip_select &
  spi->cs_gpiod, and replaced all spi->chip_select and spi->cs_gpiod
  references with the API calls.
- Created separate patch to add get & set APIs for nor->params.
---

Amit Kumar Mahapatra (15):
  spi: Replace all spi->chip_select and spi->cs_gpiod references with
    function call
  net: Replace all spi->chip_select and spi->cs_gpiod references with
    function call
  iio: imu: Replace all spi->chip_select and spi->cs_gpiod references
    with function call
  mtd: devices: Replace all spi->chip_select and spi->cs_gpiod
    references with function call
  staging: Replace all spi->chip_select and spi->cs_gpiod references
    with function call
  platform/x86: serial-multi-instantiate: Replace all spi->chip_select
    and spi->cs_gpiod references with function call
  powerpc/83xx/mpc832x_rdb: Replace all spi->chip_select references with
    function call
  ALSA: hda: cs35l41: Replace all spi->chip_select references with
    function call
  spi: Add stacked and parallel memories support in SPI core
  mtd: spi-nor: Convert macros with inline functions
  mtd: spi-nor: Add APIs to set/get nor->params
  mtd: spi-nor: Add stacked memories support in spi-nor
  spi: spi-zynqmp-gqspi: Add stacked memories support in GQSPI driver
  mtd: spi-nor: Add parallel memories support in spi-nor
  spi: spi-zynqmp-gqspi: Add parallel memories support in GQSPI driver

 arch/powerpc/platforms/83xx/mpc832x_rdb.c     |   2 +-
 drivers/iio/imu/adis16400.c                   |   2 +-
 drivers/mtd/devices/mtd_dataflash.c           |   2 +-
 drivers/mtd/spi-nor/atmel.c                   |  17 +-
 drivers/mtd/spi-nor/core.c                    | 665 +++++++++++++++---
 drivers/mtd/spi-nor/core.h                    |   8 +
 drivers/mtd/spi-nor/debugfs.c                 |   4 +-
 drivers/mtd/spi-nor/gigadevice.c              |   4 +-
 drivers/mtd/spi-nor/issi.c                    |  11 +-
 drivers/mtd/spi-nor/macronix.c                |   6 +-
 drivers/mtd/spi-nor/micron-st.c               |  39 +-
 drivers/mtd/spi-nor/otp.c                     |  48 +-
 drivers/mtd/spi-nor/sfdp.c                    |  29 +-
 drivers/mtd/spi-nor/spansion.c                |  50 +-
 drivers/mtd/spi-nor/sst.c                     |   7 +-
 drivers/mtd/spi-nor/swp.c                     |  22 +-
 drivers/mtd/spi-nor/winbond.c                 |  10 +-
 drivers/mtd/spi-nor/xilinx.c                  |  18 +-
 drivers/net/ethernet/adi/adin1110.c           |   2 +-
 drivers/net/ethernet/asix/ax88796c_main.c     |   2 +-
 drivers/net/ethernet/davicom/dm9051.c         |   2 +-
 drivers/net/ethernet/qualcomm/qca_debug.c     |   2 +-
 drivers/net/ieee802154/ca8210.c               |   2 +-
 drivers/net/wan/slic_ds26522.c                |   2 +-
 .../net/wireless/marvell/libertas/if_spi.c    |   2 +-
 drivers/net/wireless/silabs/wfx/bus_spi.c     |   2 +-
 drivers/net/wireless/st/cw1200/cw1200_spi.c   |   2 +-
 .../platform/x86/serial-multi-instantiate.c   |   3 +-
 drivers/spi/spi-altera-core.c                 |   2 +-
 drivers/spi/spi-amd.c                         |   4 +-
 drivers/spi/spi-ar934x.c                      |   2 +-
 drivers/spi/spi-armada-3700.c                 |   4 +-
 drivers/spi/spi-aspeed-smc.c                  |  13 +-
 drivers/spi/spi-at91-usart.c                  |   2 +-
 drivers/spi/spi-ath79.c                       |   4 +-
 drivers/spi/spi-atmel.c                       |  26 +-
 drivers/spi/spi-au1550.c                      |   4 +-
 drivers/spi/spi-axi-spi-engine.c              |   2 +-
 drivers/spi/spi-bcm-qspi.c                    |  10 +-
 drivers/spi/spi-bcm2835.c                     |  19 +-
 drivers/spi/spi-bcm2835aux.c                  |   4 +-
 drivers/spi/spi-bcm63xx-hsspi.c               |  30 +-
 drivers/spi/spi-bcm63xx.c                     |   2 +-
 drivers/spi/spi-bcmbca-hsspi.c                |  30 +-
 drivers/spi/spi-cadence-quadspi.c             |   5 +-
 drivers/spi/spi-cadence-xspi.c                |   4 +-
 drivers/spi/spi-cadence.c                     |   4 +-
 drivers/spi/spi-cavium.c                      |   8 +-
 drivers/spi/spi-coldfire-qspi.c               |   8 +-
 drivers/spi/spi-davinci.c                     |  18 +-
 drivers/spi/spi-dln2.c                        |   6 +-
 drivers/spi/spi-dw-core.c                     |   2 +-
 drivers/spi/spi-dw-mmio.c                     |   4 +-
 drivers/spi/spi-falcon.c                      |   2 +-
 drivers/spi/spi-fsi.c                         |   2 +-
 drivers/spi/spi-fsl-dspi.c                    |  16 +-
 drivers/spi/spi-fsl-espi.c                    |   6 +-
 drivers/spi/spi-fsl-lpspi.c                   |   2 +-
 drivers/spi/spi-fsl-qspi.c                    |   6 +-
 drivers/spi/spi-fsl-spi.c                     |   2 +-
 drivers/spi/spi-geni-qcom.c                   |   6 +-
 drivers/spi/spi-gpio.c                        |   4 +-
 drivers/spi/spi-gxp.c                         |   4 +-
 drivers/spi/spi-hisi-sfc-v3xx.c               |   2 +-
 drivers/spi/spi-img-spfi.c                    |  14 +-
 drivers/spi/spi-imx.c                         |  30 +-
 drivers/spi/spi-ingenic.c                     |   4 +-
 drivers/spi/spi-intel.c                       |   2 +-
 drivers/spi/spi-jcore.c                       |   4 +-
 drivers/spi/spi-lantiq-ssc.c                  |   6 +-
 drivers/spi/spi-mem.c                         |   4 +-
 drivers/spi/spi-meson-spicc.c                 |   2 +-
 drivers/spi/spi-microchip-core.c              |   6 +-
 drivers/spi/spi-mpc512x-psc.c                 |   8 +-
 drivers/spi/spi-mpc52xx.c                     |   2 +-
 drivers/spi/spi-mt65xx.c                      |   6 +-
 drivers/spi/spi-mt7621.c                      |   2 +-
 drivers/spi/spi-mux.c                         |   8 +-
 drivers/spi/spi-mxic.c                        |  10 +-
 drivers/spi/spi-mxs.c                         |   2 +-
 drivers/spi/spi-npcm-fiu.c                    |  20 +-
 drivers/spi/spi-nxp-fspi.c                    |  10 +-
 drivers/spi/spi-omap-uwire.c                  |   8 +-
 drivers/spi/spi-omap2-mcspi.c                 |  24 +-
 drivers/spi/spi-orion.c                       |   4 +-
 drivers/spi/spi-pci1xxxx.c                    |   4 +-
 drivers/spi/spi-pic32-sqi.c                   |   2 +-
 drivers/spi/spi-pic32.c                       |   4 +-
 drivers/spi/spi-pl022.c                       |   4 +-
 drivers/spi/spi-pxa2xx.c                      |   6 +-
 drivers/spi/spi-qcom-qspi.c                   |   2 +-
 drivers/spi/spi-rb4xx.c                       |   2 +-
 drivers/spi/spi-rockchip-sfc.c                |   2 +-
 drivers/spi/spi-rockchip.c                    |  26 +-
 drivers/spi/spi-rspi.c                        |  10 +-
 drivers/spi/spi-s3c64xx.c                     |   2 +-
 drivers/spi/spi-sc18is602.c                   |   4 +-
 drivers/spi/spi-sh-msiof.c                    |   6 +-
 drivers/spi/spi-sh-sci.c                      |   2 +-
 drivers/spi/spi-sifive.c                      |   6 +-
 drivers/spi/spi-sn-f-ospi.c                   |   2 +-
 drivers/spi/spi-st-ssc4.c                     |   2 +-
 drivers/spi/spi-stm32-qspi.c                  |  12 +-
 drivers/spi/spi-sun4i.c                       |   2 +-
 drivers/spi/spi-sun6i.c                       |   2 +-
 drivers/spi/spi-synquacer.c                   |   6 +-
 drivers/spi/spi-tegra114.c                    |  28 +-
 drivers/spi/spi-tegra20-sflash.c              |   2 +-
 drivers/spi/spi-tegra20-slink.c               |   6 +-
 drivers/spi/spi-tegra210-quad.c               |   8 +-
 drivers/spi/spi-ti-qspi.c                     |  16 +-
 drivers/spi/spi-topcliff-pch.c                |   4 +-
 drivers/spi/spi-wpcm-fiu.c                    |  12 +-
 drivers/spi/spi-xcomm.c                       |   2 +-
 drivers/spi/spi-xilinx.c                      |   6 +-
 drivers/spi/spi-xlp.c                         |   4 +-
 drivers/spi/spi-zynq-qspi.c                   |   2 +-
 drivers/spi/spi-zynqmp-gqspi.c                |  58 +-
 drivers/spi/spi.c                             | 225 ++++--
 drivers/spi/spidev.c                          |   6 +-
 drivers/staging/fbtft/fbtft-core.c            |   2 +-
 drivers/staging/greybus/spilib.c              |   2 +-
 include/linux/mtd/spi-nor.h                   |  18 +-
 include/linux/spi/spi.h                       |  34 +-
 include/trace/events/spi.h                    |  10 +-
 sound/pci/hda/cs35l41_hda_spi.c               |   2 +-
 126 files changed, 1350 insertions(+), 615 deletions(-)

-- 
2.25.1

[PATCH V6 02/15] net: Replace all spi->chip_select and spi->cs_gpiod references with function call

[Amit Kumar Mahapatra]

Supporting multi-cs in spi drivers would require the chip_select & cs_gpiod
members of struct spi_device to be an array. But changing the type of these
members to array would break the spi driver functionality. To make the
transition smoother introduced four new APIs to get/set the
spi->chip_select & spi->cs_gpiod and replaced all spi->chip_select and
spi->cs_gpiod references with get or set API calls.
While adding multi-cs support in further patches the chip_select & cs_gpiod
members of the spi_device structure would be converted to arrays & the
"idx" parameter of the APIs would be used as array index i.e.,
spi->chip_select[idx] & spi->cs_gpiod[idx] respectively.

Signed-off-by: Amit Kumar Mahapatra <amit.kumar-mahapatra@amd.com>
Reviewed-by: Michal Simek <michal.simek@amd.com>
---
 drivers/net/ethernet/adi/adin1110.c            | 2 +-
 drivers/net/ethernet/asix/ax88796c_main.c      | 2 +-
 drivers/net/ethernet/davicom/dm9051.c          | 2 +-
 drivers/net/ethernet/qualcomm/qca_debug.c      | 2 +-
 drivers/net/ieee802154/ca8210.c                | 2 +-
 drivers/net/wan/slic_ds26522.c                 | 2 +-
 drivers/net/wireless/marvell/libertas/if_spi.c | 2 +-
 drivers/net/wireless/silabs/wfx/bus_spi.c      | 2 +-
 drivers/net/wireless/st/cw1200/cw1200_spi.c    | 2 +-
 9 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/drivers/net/ethernet/adi/adin1110.c b/drivers/net/ethernet/adi/adin1110.c
index 3f316a0f4158..f5c2d7a9abc1 100644
--- a/drivers/net/ethernet/adi/adin1110.c
+++ b/drivers/net/ethernet/adi/adin1110.c
@@ -515,7 +515,7 @@ static int adin1110_register_mdiobus(struct adin1110_priv *priv,
 		return -ENOMEM;
 
 	snprintf(priv->mii_bus_name, MII_BUS_ID_SIZE, "%s-%u",
-		 priv->cfg->name, priv->spidev->chip_select);
+		 priv->cfg->name, spi_get_chipselect(priv->spidev, 0));
 
 	mii_bus->name = priv->mii_bus_name;
 	mii_bus->read = adin1110_mdio_read;
diff --git a/drivers/net/ethernet/asix/ax88796c_main.c b/drivers/net/ethernet/asix/ax88796c_main.c
index 21376c79f671..e551ffaed20d 100644
--- a/drivers/net/ethernet/asix/ax88796c_main.c
+++ b/drivers/net/ethernet/asix/ax88796c_main.c
@@ -1006,7 +1006,7 @@ static int ax88796c_probe(struct spi_device *spi)
 	ax_local->mdiobus->parent = &spi->dev;
 
 	snprintf(ax_local->mdiobus->id, MII_BUS_ID_SIZE,
-		 "ax88796c-%s.%u", dev_name(&spi->dev), spi->chip_select);
+		 "ax88796c-%s.%u", dev_name(&spi->dev), spi_get_chipselect(spi, 0));
 
 	ret = devm_mdiobus_register(&spi->dev, ax_local->mdiobus);
 	if (ret < 0) {
diff --git a/drivers/net/ethernet/davicom/dm9051.c b/drivers/net/ethernet/davicom/dm9051.c
index de7105a84747..70728b2e5f18 100644
--- a/drivers/net/ethernet/davicom/dm9051.c
+++ b/drivers/net/ethernet/davicom/dm9051.c
@@ -1123,7 +1123,7 @@ static int dm9051_mdio_register(struct board_info *db)
 	db->mdiobus->phy_mask = (u32)~BIT(1);
 	db->mdiobus->parent = &spi->dev;
 	snprintf(db->mdiobus->id, MII_BUS_ID_SIZE,
-		 "dm9051-%s.%u", dev_name(&spi->dev), spi->chip_select);
+		 "dm9051-%s.%u", dev_name(&spi->dev), spi_get_chipselect(spi, 0));
 
 	ret = devm_mdiobus_register(&spi->dev, db->mdiobus);
 	if (ret)
diff --git a/drivers/net/ethernet/qualcomm/qca_debug.c b/drivers/net/ethernet/qualcomm/qca_debug.c
index f62c39544e08..6f2fa2a42770 100644
--- a/drivers/net/ethernet/qualcomm/qca_debug.c
+++ b/drivers/net/ethernet/qualcomm/qca_debug.c
@@ -119,7 +119,7 @@ qcaspi_info_show(struct seq_file *s, void *what)
 	seq_printf(s, "SPI mode         : %x\n",
 		   qca->spi_dev->mode);
 	seq_printf(s, "SPI chip select  : %u\n",
-		   (unsigned int)qca->spi_dev->chip_select);
+		   (unsigned int)spi_get_chipselect(qca->spi_dev, 0));
 	seq_printf(s, "SPI legacy mode  : %u\n",
 		   (unsigned int)qca->legacy_mode);
 	seq_printf(s, "SPI burst length : %u\n",
diff --git a/drivers/net/ieee802154/ca8210.c b/drivers/net/ieee802154/ca8210.c
index e1a569b99e4a..7093a07141bb 100644
--- a/drivers/net/ieee802154/ca8210.c
+++ b/drivers/net/ieee802154/ca8210.c
@@ -2967,7 +2967,7 @@ static int ca8210_test_interface_init(struct ca8210_priv *priv)
 		sizeof(node_name),
 		"ca8210@%d_%d",
 		priv->spi->master->bus_num,
-		priv->spi->chip_select
+		spi_get_chipselect(priv->spi, 0)
 	);
 
 	test->ca8210_dfs_spi_int = debugfs_create_file(
diff --git a/drivers/net/wan/slic_ds26522.c b/drivers/net/wan/slic_ds26522.c
index 6063552cea9b..8a51cfcff99e 100644
--- a/drivers/net/wan/slic_ds26522.c
+++ b/drivers/net/wan/slic_ds26522.c
@@ -211,7 +211,7 @@ static int slic_ds26522_probe(struct spi_device *spi)
 
 	ret = slic_ds26522_init_configure(spi);
 	if (ret == 0)
-		pr_info("DS26522 cs%d configured\n", spi->chip_select);
+		pr_info("DS26522 cs%d configured\n", spi_get_chipselect(spi, 0));
 
 	return ret;
 }
diff --git a/drivers/net/wireless/marvell/libertas/if_spi.c b/drivers/net/wireless/marvell/libertas/if_spi.c
index ff1c7ec8c450..1225fc0e3352 100644
--- a/drivers/net/wireless/marvell/libertas/if_spi.c
+++ b/drivers/net/wireless/marvell/libertas/if_spi.c
@@ -1051,7 +1051,7 @@ static int if_spi_init_card(struct if_spi_card *card)
 				"spi->max_speed_hz=%d\n",
 				card->card_id, card->card_rev,
 				card->spi->master->bus_num,
-				card->spi->chip_select,
+				spi_get_chipselect(card->spi, 0),
 				card->spi->max_speed_hz);
 		err = if_spi_prog_helper_firmware(card, helper);
 		if (err)
diff --git a/drivers/net/wireless/silabs/wfx/bus_spi.c b/drivers/net/wireless/silabs/wfx/bus_spi.c
index 7fb1afb8ed31..160b90114aad 100644
--- a/drivers/net/wireless/silabs/wfx/bus_spi.c
+++ b/drivers/net/wireless/silabs/wfx/bus_spi.c
@@ -208,7 +208,7 @@ static int wfx_spi_probe(struct spi_device *func)
 
 	/* Trace below is also displayed by spi_setup() if compiled with DEBUG */
 	dev_dbg(&func->dev, "SPI params: CS=%d, mode=%d bits/word=%d speed=%d\n",
-		func->chip_select, func->mode, func->bits_per_word, func->max_speed_hz);
+		spi_get_chipselect(func, 0), func->mode, func->bits_per_word, func->max_speed_hz);
 	if (func->bits_per_word != 16 && func->bits_per_word != 8)
 		dev_warn(&func->dev, "unusual bits/word value: %d\n", func->bits_per_word);
 	if (func->max_speed_hz > 50000000)
diff --git a/drivers/net/wireless/st/cw1200/cw1200_spi.c b/drivers/net/wireless/st/cw1200/cw1200_spi.c
index fe0d220da44d..c82c0688b549 100644
--- a/drivers/net/wireless/st/cw1200/cw1200_spi.c
+++ b/drivers/net/wireless/st/cw1200/cw1200_spi.c
@@ -378,7 +378,7 @@ static int cw1200_spi_probe(struct spi_device *func)
 	func->mode = SPI_MODE_0;
 
 	pr_info("cw1200_wlan_spi: Probe called (CS %d M %d BPW %d CLK %d)\n",
-		func->chip_select, func->mode, func->bits_per_word,
+		spi_get_chipselect(func, 0), func->mode, func->bits_per_word,
 		func->max_speed_hz);
 
 	if (cw1200_spi_on(plat_data)) {
-- 
2.25.1

[PATCH V6 03/15] iio: imu: Replace all spi->chip_select and spi->cs_gpiod references with function call

[Amit Kumar Mahapatra]

Supporting multi-cs in spi drivers would require the chip_select & cs_gpiod
members of struct spi_device to be an array. But changing the type of these
members to array would break the spi driver functionality. To make the
transition smoother introduced four new APIs to get/set the
spi->chip_select & spi->cs_gpiod and replaced all spi->chip_select and
spi->cs_gpiod references with get or set API calls.
While adding multi-cs support in further patches the chip_select & cs_gpiod
members of the spi_device structure would be converted to arrays & the
"idx" parameter of the APIs would be used as array index i.e.,
spi->chip_select[idx] & spi->cs_gpiod[idx] respectively.

Signed-off-by: Amit Kumar Mahapatra <amit.kumar-mahapatra@amd.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Michal Simek <michal.simek@amd.com>
---
 drivers/iio/imu/adis16400.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iio/imu/adis16400.c b/drivers/iio/imu/adis16400.c
index c02fc35dceb4..3eda32e12a53 100644
--- a/drivers/iio/imu/adis16400.c
+++ b/drivers/iio/imu/adis16400.c
@@ -466,7 +466,7 @@ static int adis16400_initial_setup(struct iio_dev *indio_dev)
 
 		dev_info(&indio_dev->dev, "%s: prod_id 0x%04x at CS%d (irq %d)\n",
 			indio_dev->name, prod_id,
-			st->adis.spi->chip_select, st->adis.spi->irq);
+			spi_get_chipselect(st->adis.spi, 0), st->adis.spi->irq);
 	}
 	/* use high spi speed if possible */
 	if (st->variant->flags & ADIS16400_HAS_SLOW_MODE) {
-- 
2.25.1

[PATCH V6 04/15] mtd: devices: Replace all spi->chip_select and spi->cs_gpiod references with function call

[Amit Kumar Mahapatra]

Supporting multi-cs in spi drivers would require the chip_select & cs_gpiod
members of struct spi_device to be an array. But changing the type of these
members to array would break the spi driver functionality. To make the
transition smoother introduced four new APIs to get/set the
spi->chip_select & spi->cs_gpiod and replaced all spi->chip_select and
spi->cs_gpiod references with get or set API calls.
While adding multi-cs support in further patches the chip_select & cs_gpiod
members of the spi_device structure would be converted to arrays & the
"idx" parameter of the APIs would be used as array index i.e.,
spi->chip_select[idx] & spi->cs_gpiod[idx] respectively.

Signed-off-by: Amit Kumar Mahapatra <amit.kumar-mahapatra@amd.com>
Reviewed-by: Michal Simek <michal.simek@amd.com>
---
 drivers/mtd/devices/mtd_dataflash.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/mtd/devices/mtd_dataflash.c b/drivers/mtd/devices/mtd_dataflash.c
index 3bbaa590c768..1d3b2a94581f 100644
--- a/drivers/mtd/devices/mtd_dataflash.c
+++ b/drivers/mtd/devices/mtd_dataflash.c
@@ -639,7 +639,7 @@ static int add_dataflash_otp(struct spi_device *spi, char *name, int nr_pages,
 
 	/* name must be usable with cmdlinepart */
 	sprintf(priv->name, "spi%d.%d-%s",
-			spi->master->bus_num, spi->chip_select,
+			spi->master->bus_num, spi_get_chipselect(spi, 0),
 			name);
 
 	device = &priv->mtd;
-- 
2.25.1

[PATCH V6 05/15] staging: Replace all spi->chip_select and spi->cs_gpiod references with function call

[Amit Kumar Mahapatra]

Supporting multi-cs in spi drivers would require the chip_select & cs_gpiod
members of struct spi_device to be an array. But changing the type of these
members to array would break the spi driver functionality. To make the
transition smoother introduced four new APIs to get/set the
spi->chip_select & spi->cs_gpiod and replaced all spi->chip_select and
spi->cs_gpiod references with get or set API calls.
While adding multi-cs support in further patches the chip_select & cs_gpiod
members of the spi_device structure would be converted to arrays & the
"idx" parameter of the APIs would be used as array index i.e.,
spi->chip_select[idx] & spi->cs_gpiod[idx] respectively.

Signed-off-by: Amit Kumar Mahapatra <amit.kumar-mahapatra@amd.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Michal Simek <michal.simek@amd.com>
---
 drivers/staging/fbtft/fbtft-core.c | 2 +-
 drivers/staging/greybus/spilib.c   | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/fbtft/fbtft-core.c b/drivers/staging/fbtft/fbtft-core.c
index afaba94d1d1c..3a4abf3bae40 100644
--- a/drivers/staging/fbtft/fbtft-core.c
+++ b/drivers/staging/fbtft/fbtft-core.c
@@ -840,7 +840,7 @@ int fbtft_register_framebuffer(struct fb_info *fb_info)
 		sprintf(text1, ", %zu KiB buffer memory", par->txbuf.len >> 10);
 	if (spi)
 		sprintf(text2, ", spi%d.%d at %d MHz", spi->master->bus_num,
-			spi->chip_select, spi->max_speed_hz / 1000000);
+			spi_get_chipselect(spi, 0), spi->max_speed_hz / 1000000);
 	dev_info(fb_info->dev,
 		 "%s frame buffer, %dx%d, %d KiB video memory%s, fps=%lu%s\n",
 		 fb_info->fix.id, fb_info->var.xres, fb_info->var.yres,
diff --git a/drivers/staging/greybus/spilib.c b/drivers/staging/greybus/spilib.c
index ad0700a0bb81..efb3bec58e15 100644
--- a/drivers/staging/greybus/spilib.c
+++ b/drivers/staging/greybus/spilib.c
@@ -237,7 +237,7 @@ static struct gb_operation *gb_spi_operation_create(struct gb_spilib *spi,
 	request = operation->request->payload;
 	request->count = cpu_to_le16(count);
 	request->mode = dev->mode;
-	request->chip_select = dev->chip_select;
+	request->chip_select = spi_get_chipselect(dev, 0);
 
 	gb_xfer = &request->transfers[0];
 	tx_data = gb_xfer + count;	/* place tx data after last gb_xfer */
-- 
2.25.1

[PATCH V6 06/15] platform/x86: serial-multi-instantiate: Replace all spi->chip_select and spi->cs_gpiod references with function call

[Amit Kumar Mahapatra]

Supporting multi-cs in spi drivers would require the chip_select & cs_gpiod
members of struct spi_device to be an array. But changing the type of these
members to array would break the spi driver functionality. To make the
transition smoother introduced four new APIs to get/set the
spi->chip_select & spi->cs_gpiod and replaced all spi->chip_select and
spi->cs_gpiod references with get or set API calls.
While adding multi-cs support in further patches the chip_select & cs_gpiod
members of the spi_device structure would be converted to arrays & the
"idx" parameter of the APIs would be used as array index i.e.,
spi->chip_select[idx] & spi->cs_gpiod[idx] respectively.

Signed-off-by: Amit Kumar Mahapatra <amit.kumar-mahapatra@amd.com>
Reviewed-by: Michal Simek <michal.simek@amd.com>
---
 drivers/platform/x86/serial-multi-instantiate.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/platform/x86/serial-multi-instantiate.c b/drivers/platform/x86/serial-multi-instantiate.c
index 5362f1a7b77c..270a4700d25d 100644
--- a/drivers/platform/x86/serial-multi-instantiate.c
+++ b/drivers/platform/x86/serial-multi-instantiate.c
@@ -139,7 +139,8 @@ static int smi_spi_probe(struct platform_device *pdev, struct smi *smi,
 			goto error;
 		}
 
-		dev_dbg(dev, "SPI device %s using chip select %u", name, spi_dev->chip_select);
+		dev_dbg(dev, "SPI device %s using chip select %u", name,
+			spi_get_chipselect(spi_dev, 0));
 
 		smi->spi_devs[i] = spi_dev;
 		smi->spi_num++;
-- 
2.25.1

[PATCH V6 07/15] powerpc/83xx/mpc832x_rdb: Replace all spi->chip_select references with function call

[Amit Kumar Mahapatra]

Supporting multi-cs in spi drivers would require the chip_select & cs_gpiod
members of struct spi_device to be an array. But changing the type of these
members to array would break the spi driver functionality. To make the
transition smoother introduced four new APIs to get/set the
spi->chip_select & spi->cs_gpiod and replaced all spi->chip_select and
spi->cs_gpiod references with get or set API calls.
While adding multi-cs support in further patches the chip_select & cs_gpiod
members of the spi_device structure would be converted to arrays & the
"idx" parameter of the APIs would be used as array index i.e.,
spi->chip_select[idx] & spi->cs_gpiod[idx] respectively.

Signed-off-by: Amit Kumar Mahapatra <amit.kumar-mahapatra@amd.com>
---
 arch/powerpc/platforms/83xx/mpc832x_rdb.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/platforms/83xx/mpc832x_rdb.c b/arch/powerpc/platforms/83xx/mpc832x_rdb.c
index caa96edf0e72..4ab1d48cd229 100644
--- a/arch/powerpc/platforms/83xx/mpc832x_rdb.c
+++ b/arch/powerpc/platforms/83xx/mpc832x_rdb.c
@@ -144,7 +144,7 @@ static int __init fsl_spi_init(struct spi_board_info *board_infos,
 
 static void mpc83xx_spi_cs_control(struct spi_device *spi, bool on)
 {
-	pr_debug("%s %d %d\n", __func__, spi->chip_select, on);
+	pr_debug("%s %d %d\n", __func__, spi_get_chipselect(spi, 0), on);
 	par_io_data_set(3, 13, on);
 }
 
-- 
2.25.1

[PATCH V6 08/15] ALSA: hda: cs35l41: Replace all spi->chip_select references with function call

[Amit Kumar Mahapatra]

Supporting multi-cs in spi drivers would require the chip_select & cs_gpiod
members of struct spi_device to be an array. But changing the type of these
members to array would break the spi driver functionality. To make the
transition smoother introduced four new APIs to get/set the
spi->chip_select & spi->cs_gpiod and replaced all spi->chip_select and
spi->cs_gpiod references with get or set API calls.
While adding multi-cs support in further patches the chip_select & cs_gpiod
members of the spi_device structure would be converted to arrays & the
"idx" parameter of the APIs would be used as array index i.e.,
spi->chip_select[idx] & spi->cs_gpiod[idx] respectively.

Signed-off-by: Amit Kumar Mahapatra <amit.kumar-mahapatra@amd.com>
---
 sound/pci/hda/cs35l41_hda_spi.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sound/pci/hda/cs35l41_hda_spi.c b/sound/pci/hda/cs35l41_hda_spi.c
index 71979cfb4d7e..eb287aa5f782 100644
--- a/sound/pci/hda/cs35l41_hda_spi.c
+++ b/sound/pci/hda/cs35l41_hda_spi.c
@@ -25,7 +25,7 @@ static int cs35l41_hda_spi_probe(struct spi_device *spi)
 	else
 		return -ENODEV;
 
-	return cs35l41_hda_probe(&spi->dev, device_name, spi->chip_select, spi->irq,
+	return cs35l41_hda_probe(&spi->dev, device_name, spi_get_chipselect(spi, 0), spi->irq,
 				 devm_regmap_init_spi(spi, &cs35l41_regmap_spi));
 }
 
-- 
2.25.1

[PATCH V6 09/15] spi: Add stacked and parallel memories support in SPI core

[Amit Kumar Mahapatra]

For supporting multiple CS the SPI device need to be aware of all the CS
values. So, the "chip_select" member in the spi_device structure is now an
array that holds all the CS values.

spi_device structure now has a "cs_index_mask" member. This acts as an
index to the chip_select array. If nth bit of spi->cs_index_mask is set
then the driver would assert spi->chip_select[n].

In parallel mode all the chip selects are asserted/de-asserted
simultaneously and each byte of data is stored in both devices, the even
bits in one, the odd bits in the other. The split is automatically handled
by the GQSPI controller. The GQSPI controller supports a maximum of two
flashes connected in parallel mode. A "multi-cs-cap" flag is added in the
spi controntroller data, through ctlr->multi-cs-cap the spi core will make
sure that the controller is capable of handling multiple chip selects at
once.

For supporting multiple CS via GPIO the cs_gpiod member of the spi_device
structure is now an array that holds the gpio descriptor for each
chipselect.

Multi CS support using GPIO is not tested due to unavailability of
necessary hardware setup.

Signed-off-by: Amit Kumar Mahapatra <amit.kumar-mahapatra@amd.com>
---
 drivers/spi/spi.c       | 225 +++++++++++++++++++++++++++-------------
 include/linux/spi/spi.h |  34 ++++--
 2 files changed, 182 insertions(+), 77 deletions(-)

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index c725b4bab7af..742bd688381c 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -612,10 +612,17 @@ static int spi_dev_check(struct device *dev, void *data)
 {
 	struct spi_device *spi = to_spi_device(dev);
 	struct spi_device *new_spi = data;
-
-	if (spi->controller == new_spi->controller &&
-	    spi_get_chipselect(spi, 0) == spi_get_chipselect(new_spi, 0))
-		return -EBUSY;
+	int idx, nw_idx;
+
+	if (spi->controller == new_spi->controller) {
+		for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) {
+			for (nw_idx = 0; nw_idx < SPI_CS_CNT_MAX; nw_idx++) {
+				if (spi_get_chipselect(spi, idx) ==
+				    spi_get_chipselect(new_spi, nw_idx))
+					return -EBUSY;
+			}
+		}
+	}
 	return 0;
 }
 
@@ -629,7 +636,7 @@ static int __spi_add_device(struct spi_device *spi)
 {
 	struct spi_controller *ctlr = spi->controller;
 	struct device *dev = ctlr->dev.parent;
-	int status;
+	int status, idx;
 
 	/*
 	 * We need to make sure there's no other device with this
@@ -638,8 +645,7 @@ static int __spi_add_device(struct spi_device *spi)
 	 */
 	status = bus_for_each_dev(&spi_bus_type, NULL, spi, spi_dev_check);
 	if (status) {
-		dev_err(dev, "chipselect %d already in use\n",
-				spi_get_chipselect(spi, 0));
+		dev_err(dev, "chipselect %d already in use\n", spi_get_chipselect(spi, 0));
 		return status;
 	}
 
@@ -649,8 +655,10 @@ static int __spi_add_device(struct spi_device *spi)
 		return -ENODEV;
 	}
 
-	if (ctlr->cs_gpiods)
-		spi_set_csgpiod(spi, 0, ctlr->cs_gpiods[spi_get_chipselect(spi, 0)]);
+	if (ctlr->cs_gpiods) {
+		for (idx = 0; idx < SPI_CS_CNT_MAX; idx++)
+			spi_set_csgpiod(spi, idx, ctlr->cs_gpiods[spi_get_chipselect(spi, idx)]);
+	}
 
 	/*
 	 * Drivers may modify this initial i/o setup, but will
@@ -690,13 +698,15 @@ int spi_add_device(struct spi_device *spi)
 {
 	struct spi_controller *ctlr = spi->controller;
 	struct device *dev = ctlr->dev.parent;
-	int status;
+	int status, idx;
 
-	/* Chipselects are numbered 0..max; validate. */
-	if (spi_get_chipselect(spi, 0) >= ctlr->num_chipselect) {
-		dev_err(dev, "cs%d >= max %d\n", spi_get_chipselect(spi, 0),
-			ctlr->num_chipselect);
-		return -EINVAL;
+	for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) {
+		/* Chipselects are numbered 0..max; validate. */
+		if (spi_get_chipselect(spi, idx) >= ctlr->num_chipselect) {
+			dev_err(dev, "cs%d >= max %d\n", spi_get_chipselect(spi, idx),
+				ctlr->num_chipselect);
+			return -EINVAL;
+		}
 	}
 
 	/* Set the bus ID string */
@@ -713,12 +723,15 @@ static int spi_add_device_locked(struct spi_device *spi)
 {
 	struct spi_controller *ctlr = spi->controller;
 	struct device *dev = ctlr->dev.parent;
+	int idx;
 
-	/* Chipselects are numbered 0..max; validate. */
-	if (spi_get_chipselect(spi, 0) >= ctlr->num_chipselect) {
-		dev_err(dev, "cs%d >= max %d\n", spi_get_chipselect(spi, 0),
-			ctlr->num_chipselect);
-		return -EINVAL;
+	for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) {
+		/* Chipselects are numbered 0..max; validate. */
+		if (spi_get_chipselect(spi, idx) >= ctlr->num_chipselect) {
+			dev_err(dev, "cs%d >= max %d\n", spi_get_chipselect(spi, idx),
+				ctlr->num_chipselect);
+			return -EINVAL;
+		}
 	}
 
 	/* Set the bus ID string */
@@ -966,58 +979,119 @@ static void spi_res_release(struct spi_controller *ctlr, struct spi_message *mes
 static void spi_set_cs(struct spi_device *spi, bool enable, bool force)
 {
 	bool activate = enable;
+	u32 cs_num = __ffs(spi->cs_index_mask);
+	int idx;
 
 	/*
-	 * Avoid calling into the driver (or doing delays) if the chip select
-	 * isn't actually changing from the last time this was called.
+	 * In parallel mode all the chip selects are asserted/de-asserted
+	 * at once
 	 */
-	if (!force && ((enable && spi->controller->last_cs == spi_get_chipselect(spi, 0)) ||
-		       (!enable && spi->controller->last_cs != spi_get_chipselect(spi, 0))) &&
-	    (spi->controller->last_cs_mode_high == (spi->mode & SPI_CS_HIGH)))
-		return;
-
-	trace_spi_set_cs(spi, activate);
-
-	spi->controller->last_cs = enable ? spi_get_chipselect(spi, 0) : -1;
-	spi->controller->last_cs_mode_high = spi->mode & SPI_CS_HIGH;
-
-	if ((spi_get_csgpiod(spi, 0) || !spi->controller->set_cs_timing) && !activate)
-		spi_delay_exec(&spi->cs_hold, NULL);
-
-	if (spi->mode & SPI_CS_HIGH)
-		enable = !enable;
+	if ((spi->cs_index_mask & SPI_PARALLEL_CS_MASK) == SPI_PARALLEL_CS_MASK) {
+		spi->controller->last_cs_mode_high = spi->mode & SPI_CS_HIGH;
+
+		if ((spi_get_csgpiod(spi, 0) || !spi->controller->set_cs_timing) && !activate)
+			spi_delay_exec(&spi->cs_hold, NULL);
+
+		if (spi->mode & SPI_CS_HIGH)
+			enable = !enable;
+
+		if (spi_get_csgpiod(spi, 0) && spi_get_csgpiod(spi, 1)) {
+			if (!(spi->mode & SPI_NO_CS)) {
+				/*
+				 * Historically ACPI has no means of the GPIO polarity and
+				 * thus the SPISerialBus() resource defines it on the per-chip
+				 * basis. In order to avoid a chain of negations, the GPIO
+				 * polarity is considered being Active High. Even for the cases
+				 * when _DSD() is involved (in the updated versions of ACPI)
+				 * the GPIO CS polarity must be defined Active High to avoid
+				 * ambiguity. That's why we use enable, that takes SPI_CS_HIGH
+				 * into account.
+				 */
+				if (has_acpi_companion(&spi->dev)) {
+					for (idx = 0; idx < SPI_CS_CNT_MAX; idx++)
+						gpiod_set_value_cansleep(spi_get_csgpiod(spi, idx),
+									 !enable);
+				} else {
+					for (idx = 0; idx < SPI_CS_CNT_MAX; idx++)
+						/* Polarity handled by GPIO library */
+						gpiod_set_value_cansleep(spi_get_csgpiod(spi, idx),
+									 activate);
+				}
+			}
+			/* Some SPI masters need both GPIO CS & slave_select */
+			if ((spi->controller->flags & SPI_MASTER_GPIO_SS) &&
+			    spi->controller->set_cs)
+				spi->controller->set_cs(spi, !enable);
+			else if (spi->controller->set_cs)
+				spi->controller->set_cs(spi, !enable);
+		}
 
-	if (spi_get_csgpiod(spi, 0)) {
-		if (!(spi->mode & SPI_NO_CS)) {
-			/*
-			 * Historically ACPI has no means of the GPIO polarity and
-			 * thus the SPISerialBus() resource defines it on the per-chip
-			 * basis. In order to avoid a chain of negations, the GPIO
-			 * polarity is considered being Active High. Even for the cases
-			 * when _DSD() is involved (in the updated versions of ACPI)
-			 * the GPIO CS polarity must be defined Active High to avoid
-			 * ambiguity. That's why we use enable, that takes SPI_CS_HIGH
-			 * into account.
-			 */
-			if (has_acpi_companion(&spi->dev))
-				gpiod_set_value_cansleep(spi_get_csgpiod(spi, 0), !enable);
-			else
-				/* Polarity handled by GPIO library */
-				gpiod_set_value_cansleep(spi_get_csgpiod(spi, 0), activate);
+		for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) {
+			if (spi_get_csgpiod(spi, idx) || !spi->controller->set_cs_timing) {
+				if (activate)
+					spi_delay_exec(&spi->cs_setup, NULL);
+				else
+					spi_delay_exec(&spi->cs_inactive, NULL);
+			}
 		}
-		/* Some SPI masters need both GPIO CS & slave_select */
-		if ((spi->controller->flags & SPI_MASTER_GPIO_SS) &&
-		    spi->controller->set_cs)
+	} else {
+		/*
+		 * Avoid calling into the driver (or doing delays) if the chip select
+		 * isn't actually changing from the last time this was called.
+		 */
+		if (!force && ((enable && spi->controller->last_cs ==
+				spi_get_chipselect(spi, cs_num)) ||
+				(!enable && spi->controller->last_cs !=
+				 spi_get_chipselect(spi, cs_num))) &&
+		    (spi->controller->last_cs_mode_high ==
+		     (spi->mode & SPI_CS_HIGH)))
+			return;
+
+		trace_spi_set_cs(spi, activate);
+
+		spi->controller->last_cs = enable ? spi_get_chipselect(spi, cs_num) : -1;
+		spi->controller->last_cs_mode_high = spi->mode & SPI_CS_HIGH;
+
+		if ((spi_get_csgpiod(spi, cs_num) || !spi->controller->set_cs_timing) && !activate)
+			spi_delay_exec(&spi->cs_hold, NULL);
+
+		if (spi->mode & SPI_CS_HIGH)
+			enable = !enable;
+
+		if (spi_get_csgpiod(spi, cs_num)) {
+			if (!(spi->mode & SPI_NO_CS)) {
+				/*
+				 * Historically ACPI has no means of the GPIO polarity and
+				 * thus the SPISerialBus() resource defines it on the per-chip
+				 * basis. In order to avoid a chain of negations, the GPIO
+				 * polarity is considered being Active High. Even for the cases
+				 * when _DSD() is involved (in the updated versions of ACPI)
+				 * the GPIO CS polarity must be defined Active High to avoid
+				 * ambiguity. That's why we use enable, that takes SPI_CS_HIGH
+				 * into account.
+				 */
+				if (has_acpi_companion(&spi->dev))
+					gpiod_set_value_cansleep(spi_get_csgpiod(spi, cs_num),
+								 !enable);
+				else
+					/* Polarity handled by GPIO library */
+					gpiod_set_value_cansleep(spi_get_csgpiod(spi, cs_num),
+								 activate);
+			}
+			/* Some SPI masters need both GPIO CS & slave_select */
+			if ((spi->controller->flags & SPI_MASTER_GPIO_SS) &&
+			    spi->controller->set_cs)
+				spi->controller->set_cs(spi, !enable);
+		} else if (spi->controller->set_cs) {
 			spi->controller->set_cs(spi, !enable);
-	} else if (spi->controller->set_cs) {
-		spi->controller->set_cs(spi, !enable);
-	}
+		}
 
-	if (spi_get_csgpiod(spi, 0) || !spi->controller->set_cs_timing) {
-		if (activate)
-			spi_delay_exec(&spi->cs_setup, NULL);
-		else
-			spi_delay_exec(&spi->cs_inactive, NULL);
+		if (spi_get_csgpiod(spi, cs_num) || !spi->controller->set_cs_timing) {
+			if (activate)
+				spi_delay_exec(&spi->cs_setup, NULL);
+			else
+				spi_delay_exec(&spi->cs_inactive, NULL);
+		}
 	}
 }
 
@@ -2246,8 +2320,8 @@ static void of_spi_parse_dt_cs_delay(struct device_node *nc,
 static int of_spi_parse_dt(struct spi_controller *ctlr, struct spi_device *spi,
 			   struct device_node *nc)
 {
-	u32 value;
-	int rc;
+	u32 value, cs[SPI_CS_CNT_MAX] = {0};
+	int rc, idx;
 
 	/* Mode (clock phase/polarity/etc.) */
 	if (of_property_read_bool(nc, "spi-cpha"))
@@ -2320,13 +2394,21 @@ static int of_spi_parse_dt(struct spi_controller *ctlr, struct spi_device *spi,
 	}
 
 	/* Device address */
-	rc = of_property_read_u32(nc, "reg", &value);
-	if (rc) {
+	rc = of_property_read_variable_u32_array(nc, "reg", &cs[0], 1,
+						 SPI_CS_CNT_MAX);
+	if (rc < 0 || rc > ctlr->num_chipselect) {
 		dev_err(&ctlr->dev, "%pOF has no valid 'reg' property (%d)\n",
 			nc, rc);
 		return rc;
+	} else if ((of_property_read_bool(nc, "parallel-memories")) &&
+		   (!ctlr->multi_cs_cap)) {
+		dev_err(&ctlr->dev, "SPI controller doesn't support multi CS\n");
+		return -EINVAL;
 	}
-	spi_set_chipselect(spi, 0, value);
+	for (idx = 0; idx < rc; idx++)
+		spi_set_chipselect(spi, idx, cs[idx]);
+	/* By default set the spi->cs_index_mask as 1 */
+	spi->cs_index_mask = 0x01;
 
 	/* Device speed */
 	if (!of_property_read_u32(nc, "spi-max-frequency", &value))
@@ -3846,6 +3928,7 @@ static int __spi_validate(struct spi_device *spi, struct spi_message *message)
 	struct spi_controller *ctlr = spi->controller;
 	struct spi_transfer *xfer;
 	int w_size;
+	u32 cs_num = __ffs(spi->cs_index_mask);
 
 	if (list_empty(&message->transfers))
 		return -EINVAL;
@@ -3858,7 +3941,7 @@ static int __spi_validate(struct spi_device *spi, struct spi_message *message)
 	 * cs_change is set for each transfer.
 	 */
 	if ((spi->mode & SPI_CS_WORD) && (!(ctlr->mode_bits & SPI_CS_WORD) ||
-					  spi_get_csgpiod(spi, 0))) {
+					  spi_get_csgpiod(spi, cs_num))) {
 		size_t maxsize;
 		int ret;
 
diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
index bdb35a91b4bf..452682aa1a39 100644
--- a/include/linux/spi/spi.h
+++ b/include/linux/spi/spi.h
@@ -19,6 +19,11 @@
 #include <linux/acpi.h>
 #include <linux/u64_stats_sync.h>
 
+/* Max no. of CS supported per spi device */
+#define SPI_CS_CNT_MAX 2
+
+/* chip select mask */
+#define SPI_PARALLEL_CS_MASK	(BIT(0) | BIT(1))
 struct dma_chan;
 struct software_node;
 struct ptp_system_timestamp;
@@ -166,6 +171,7 @@ extern void spi_transfer_cs_change_delay_exec(struct spi_message *msg,
  *	deasserted. If @cs_change_delay is used from @spi_transfer, then the
  *	two delays will be added up.
  * @pcpu_statistics: statistics for the spi_device
+ * @cs_index_mask: Bit mask of the active chipselect(s) in the chipselect array
  *
  * A @spi_device is used to interchange data between an SPI slave
  * (usually a discrete chip) and CPU memory.
@@ -181,7 +187,7 @@ struct spi_device {
 	struct spi_controller	*controller;
 	struct spi_controller	*master;	/* Compatibility layer */
 	u32			max_speed_hz;
-	u8			chip_select;
+	u8			chip_select[SPI_CS_CNT_MAX];
 	u8			bits_per_word;
 	bool			rt;
 #define SPI_NO_TX	BIT(31)		/* No transmit wire */
@@ -202,7 +208,7 @@ struct spi_device {
 	void			*controller_data;
 	char			modalias[SPI_NAME_SIZE];
 	const char		*driver_override;
-	struct gpio_desc	*cs_gpiod;	/* Chip select gpio desc */
+	struct gpio_desc	*cs_gpiod[SPI_CS_CNT_MAX];	/* Chip select gpio desc */
 	struct spi_delay	word_delay; /* Inter-word delay */
 	/* CS delays */
 	struct spi_delay	cs_setup;
@@ -212,6 +218,13 @@ struct spi_device {
 	/* The statistics */
 	struct spi_statistics __percpu	*pcpu_statistics;
 
+	/* Bit mask of the chipselect(s) that the driver need to use from
+	 * the chipselect array.When the controller is capable to handle
+	 * multiple chip selects & memories are connected in parallel
+	 * then more than one bit need to be set in cs_index_mask.
+	 */
+	u32			cs_index_mask : 2;
+
 	/*
 	 * likely need more hooks for more protocol options affecting how
 	 * the controller talks to each chip, like:
@@ -268,22 +281,22 @@ static inline void *spi_get_drvdata(struct spi_device *spi)
 
 static inline u8 spi_get_chipselect(struct spi_device *spi, u8 idx)
 {
-	return spi->chip_select;
+	return spi->chip_select[idx];
 }
 
 static inline void spi_set_chipselect(struct spi_device *spi, u8 idx, u8 chipselect)
 {
-	spi->chip_select = chipselect;
+	spi->chip_select[idx] = chipselect;
 }
 
 static inline struct gpio_desc *spi_get_csgpiod(struct spi_device *spi, u8 idx)
 {
-	return spi->cs_gpiod;
+	return spi->cs_gpiod[idx];
 }
 
 static inline void spi_set_csgpiod(struct spi_device *spi, u8 idx, struct gpio_desc *csgpiod)
 {
-	spi->cs_gpiod = csgpiod;
+	spi->cs_gpiod[idx] = csgpiod;
 }
 
 /**
@@ -388,6 +401,8 @@ extern struct spi_device *spi_new_ancillary_device(struct spi_device *spi, u8 ch
  * @bus_lock_spinlock: spinlock for SPI bus locking
  * @bus_lock_mutex: mutex for exclusion of multiple callers
  * @bus_lock_flag: indicates that the SPI bus is locked for exclusive use
+ * @multi_cs_cap: indicates that the SPI Controller can assert/de-assert
+ *	more than one chip select at once.
  * @setup: updates the device mode and clocking records used by a
  *	device's SPI controller; protocol code may call this.  This
  *	must fail if an unrecognized or unsupported mode is requested.
@@ -585,6 +600,13 @@ struct spi_controller {
 	/* Flag indicating that the SPI bus is locked for exclusive use */
 	bool			bus_lock_flag;
 
+	/*
+	 * Flag indicating that the spi-controller has multi chip select
+	 * capability and can assert/de-assert more than one chip select
+	 * at once.
+	 */
+	bool			multi_cs_cap;
+
 	/* Setup mode and clock, etc (spi driver may call many times).
 	 *
 	 * IMPORTANT:  this may be called when transfers to another
-- 
2.25.1

[PATCH V6 10/15] mtd: spi-nor: Convert macros with inline functions

[Amit Kumar Mahapatra]

In further patches the nor->params references in
spi_nor_otp_region_len(nor) & spi_nor_otp_n_regions(nor) macros will be
replaced with spi_nor_get_params() API. To make the transition smoother,
first converting the macros into static inline functions.

Suggested-by: Michal Simek <michal.simek@amd.com>
Signed-off-by: Amit Kumar Mahapatra <amit.kumar-mahapatra@amd.com>
---
 drivers/mtd/spi-nor/otp.c | 23 +++++++++++++++++++++--
 1 file changed, 21 insertions(+), 2 deletions(-)

diff --git a/drivers/mtd/spi-nor/otp.c b/drivers/mtd/spi-nor/otp.c
index 00ab0d2d6d2f..3d75899de303 100644
--- a/drivers/mtd/spi-nor/otp.c
+++ b/drivers/mtd/spi-nor/otp.c
@@ -11,8 +11,27 @@
 
 #include "core.h"
 
-#define spi_nor_otp_region_len(nor) ((nor)->params->otp.org->len)
-#define spi_nor_otp_n_regions(nor) ((nor)->params->otp.org->n_regions)
+/**
+ * spi_nor_otp_region_len() - get size of one OTP region in bytes
+ * @nor:        pointer to 'struct spi_nor'
+ *
+ * Return: size of one OTP region in bytes
+ */
+static inline unsigned int spi_nor_otp_region_len(struct spi_nor *nor)
+{
+	return nor->params->otp.org->len;
+}
+
+/**
+ * spi_nor_otp_n_regions() - get number of individual OTP regions
+ * @nor:        pointer to 'struct spi_nor'
+ *
+ * Return: number of individual OTP regions
+ */
+static inline unsigned int spi_nor_otp_n_regions(struct spi_nor *nor)
+{
+	return nor->params->otp.org->n_regions;
+}
 
 /**
  * spi_nor_otp_read_secr() - read security register
-- 
2.25.1

[PATCH V6 11/15] mtd: spi-nor: Add APIs to set/get nor->params

[Amit Kumar Mahapatra]

Supporting multi-cs in spi-nor would require the *params member of
struct spi_nor to be an array. To make the transition smoother introduced
spi_nor_get_params() & spi_nor_set_params() APIs to get & set nor->params,
added a new local variable (struct spi_nor_flash_parameter *params) to hold
the return value of the spi_nor_get_params() function call and replaced all
nor->params references with the "params".
While adding multi-cs support in further patches the *params member of the
spi_nor structure would be converted to arrays & the "idx" parameter of
the APIs would be used as array index i.e., nor->params[idx].

Signed-off-by: Amit Kumar Mahapatra <amit.kumar-mahapatra@amd.com>
---
 drivers/mtd/spi-nor/atmel.c      |  17 ++--
 drivers/mtd/spi-nor/core.c       | 129 ++++++++++++++++++++-----------
 drivers/mtd/spi-nor/debugfs.c    |   4 +-
 drivers/mtd/spi-nor/gigadevice.c |   4 +-
 drivers/mtd/spi-nor/issi.c       |  11 ++-
 drivers/mtd/spi-nor/macronix.c   |   6 +-
 drivers/mtd/spi-nor/micron-st.c  |  34 +++++---
 drivers/mtd/spi-nor/otp.c        |  29 ++++---
 drivers/mtd/spi-nor/sfdp.c       |  29 ++++---
 drivers/mtd/spi-nor/spansion.c   |  50 +++++++-----
 drivers/mtd/spi-nor/sst.c        |   7 +-
 drivers/mtd/spi-nor/swp.c        |  22 ++++--
 drivers/mtd/spi-nor/winbond.c    |  10 ++-
 drivers/mtd/spi-nor/xilinx.c     |  18 +++--
 include/linux/mtd/spi-nor.h      |  10 +++
 15 files changed, 254 insertions(+), 126 deletions(-)

diff --git a/drivers/mtd/spi-nor/atmel.c b/drivers/mtd/spi-nor/atmel.c
index 656dd80a0be7..57ca9f5ee205 100644
--- a/drivers/mtd/spi-nor/atmel.c
+++ b/drivers/mtd/spi-nor/atmel.c
@@ -23,10 +23,11 @@ static int at25fs_nor_lock(struct spi_nor *nor, loff_t ofs, uint64_t len)
 
 static int at25fs_nor_unlock(struct spi_nor *nor, loff_t ofs, uint64_t len)
 {
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
 	int ret;
 
 	/* We only support unlocking the whole flash array */
-	if (ofs || len != nor->params->size)
+	if (ofs || len != params->size)
 		return -EINVAL;
 
 	/* Write 0x00 to the status register to disable write protection */
@@ -50,7 +51,9 @@ static const struct spi_nor_locking_ops at25fs_nor_locking_ops = {
 
 static void at25fs_nor_late_init(struct spi_nor *nor)
 {
-	nor->params->locking_ops = &at25fs_nor_locking_ops;
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
+
+	params->locking_ops = &at25fs_nor_locking_ops;
 }
 
 static const struct spi_nor_fixups at25fs_nor_fixups = {
@@ -69,11 +72,12 @@ static const struct spi_nor_fixups at25fs_nor_fixups = {
 static int atmel_nor_set_global_protection(struct spi_nor *nor, loff_t ofs,
 					   uint64_t len, bool is_protect)
 {
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
 	int ret;
 	u8 sr;
 
 	/* We only support locking the whole flash array */
-	if (ofs || len != nor->params->size)
+	if (ofs || len != params->size)
 		return -EINVAL;
 
 	ret = spi_nor_read_sr(nor, nor->bouncebuf);
@@ -131,9 +135,10 @@ static int atmel_nor_global_unprotect(struct spi_nor *nor, loff_t ofs,
 static int atmel_nor_is_global_protected(struct spi_nor *nor, loff_t ofs,
 					 uint64_t len)
 {
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
 	int ret;
 
-	if (ofs >= nor->params->size || (ofs + len) > nor->params->size)
+	if (ofs >= params->size || (ofs + len) > params->size)
 		return -EINVAL;
 
 	ret = spi_nor_read_sr(nor, nor->bouncebuf);
@@ -151,7 +156,9 @@ static const struct spi_nor_locking_ops atmel_nor_global_protection_ops = {
 
 static void atmel_nor_global_protection_late_init(struct spi_nor *nor)
 {
-	nor->params->locking_ops = &atmel_nor_global_protection_ops;
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
+
+	params->locking_ops = &atmel_nor_global_protection_ops;
 }
 
 static const struct spi_nor_fixups atmel_nor_global_protection_fixups = {
diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c
index 0a78045ca1d9..66b6934b4465 100644
--- a/drivers/mtd/spi-nor/core.c
+++ b/drivers/mtd/spi-nor/core.c
@@ -448,14 +448,15 @@ int spi_nor_read_id(struct spi_nor *nor, u8 naddr, u8 ndummy, u8 *id,
  */
 int spi_nor_read_sr(struct spi_nor *nor, u8 *sr)
 {
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
 	int ret;
 
 	if (nor->spimem) {
 		struct spi_mem_op op = SPI_NOR_RDSR_OP(sr);
 
 		if (nor->reg_proto == SNOR_PROTO_8_8_8_DTR) {
-			op.addr.nbytes = nor->params->rdsr_addr_nbytes;
-			op.dummy.nbytes = nor->params->rdsr_dummy;
+			op.addr.nbytes = params->rdsr_addr_nbytes;
+			op.dummy.nbytes = params->rdsr_dummy;
 			/*
 			 * We don't want to read only one byte in DTR mode. So,
 			 * read 2 and then discard the second byte.
@@ -596,9 +597,11 @@ int spi_nor_sr_ready(struct spi_nor *nor)
  */
 static int spi_nor_ready(struct spi_nor *nor)
 {
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
+
 	/* Flashes might override the standard routine. */
-	if (nor->params->ready)
-		return nor->params->ready(nor);
+	if (params->ready)
+		return params->ready(nor);
 
 	return spi_nor_sr_ready(nor);
 }
@@ -760,6 +763,7 @@ static int spi_nor_write_sr1_and_check(struct spi_nor *nor, u8 sr1)
  */
 static int spi_nor_write_16bit_sr_and_check(struct spi_nor *nor, u8 sr1)
 {
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
 	int ret;
 	u8 *sr_cr = nor->bouncebuf;
 	u8 cr_written;
@@ -769,7 +773,7 @@ static int spi_nor_write_16bit_sr_and_check(struct spi_nor *nor, u8 sr1)
 		ret = spi_nor_read_cr(nor, &sr_cr[1]);
 		if (ret)
 			return ret;
-	} else if (nor->params->quad_enable) {
+	} else if (params->quad_enable) {
 		/*
 		 * If the Status Register 2 Read command (35h) is not
 		 * supported, we should at least be sure we don't
@@ -777,7 +781,7 @@ static int spi_nor_write_16bit_sr_and_check(struct spi_nor *nor, u8 sr1)
 		 *
 		 * We can safely assume that when the Quad Enable method is
 		 * set, the value of the QE bit is one, as a consequence of the
-		 * nor->params->quad_enable() call.
+		 * params->quad_enable() call.
 		 *
 		 * We can safely assume that the Quad Enable bit is present in
 		 * the Status Register 2 at BIT(1). According to the JESD216
@@ -1048,17 +1052,21 @@ static u8 spi_nor_convert_3to4_erase(u8 opcode)
 
 static bool spi_nor_has_uniform_erase(const struct spi_nor *nor)
 {
-	return !!nor->params->erase_map.uniform_erase_type;
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
+
+	return !!params->erase_map.uniform_erase_type;
 }
 
 static void spi_nor_set_4byte_opcodes(struct spi_nor *nor)
 {
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
+
 	nor->read_opcode = spi_nor_convert_3to4_read(nor->read_opcode);
 	nor->program_opcode = spi_nor_convert_3to4_program(nor->program_opcode);
 	nor->erase_opcode = spi_nor_convert_3to4_erase(nor->erase_opcode);
 
 	if (!spi_nor_has_uniform_erase(nor)) {
-		struct spi_nor_erase_map *map = &nor->params->erase_map;
+		struct spi_nor_erase_map *map = &params->erase_map;
 		struct spi_nor_erase_type *erase;
 		int i;
 
@@ -1095,10 +1103,12 @@ void spi_nor_unlock_and_unprep(struct spi_nor *nor)
 
 static u32 spi_nor_convert_addr(struct spi_nor *nor, loff_t addr)
 {
-	if (!nor->params->convert_addr)
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
+
+	if (!params->convert_addr)
 		return addr;
 
-	return nor->params->convert_addr(nor, addr);
+	return params->convert_addr(nor, addr);
 }
 
 /*
@@ -1318,7 +1328,8 @@ static int spi_nor_init_erase_cmd_list(struct spi_nor *nor,
 				       struct list_head *erase_list,
 				       u64 addr, u32 len)
 {
-	const struct spi_nor_erase_map *map = &nor->params->erase_map;
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
+	const struct spi_nor_erase_map *map = &params->erase_map;
 	const struct spi_nor_erase_type *erase, *prev_erase = NULL;
 	struct spi_nor_erase_region *region;
 	struct spi_nor_erase_command *cmd = NULL;
@@ -1746,12 +1757,16 @@ static int spi_nor_write(struct mtd_info *mtd, loff_t to, size_t len,
 	size_t *retlen, const u_char *buf)
 {
 	struct spi_nor *nor = mtd_to_spi_nor(mtd);
+	struct spi_nor_flash_parameter *params;
 	size_t page_offset, page_remain, i;
 	ssize_t ret;
-	u32 page_size = nor->params->page_size;
+	u32 page_size;
 
 	dev_dbg(nor->dev, "to 0x%08x, len %zd\n", (u32)to, len);
 
+	params = spi_nor_get_params(nor, 0);
+	page_size = params->page_size;
+
 	ret = spi_nor_lock_and_prep(nor);
 	if (ret)
 		return ret;
@@ -1903,6 +1918,8 @@ int spi_nor_hwcaps_pp2cmd(u32 hwcaps)
 static int spi_nor_spimem_check_op(struct spi_nor *nor,
 				   struct spi_mem_op *op)
 {
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
+
 	/*
 	 * First test with 4 address bytes. The opcode itself might
 	 * be a 3B addressing opcode but we don't care, because
@@ -1911,7 +1928,7 @@ static int spi_nor_spimem_check_op(struct spi_nor *nor,
 	 */
 	op->addr.nbytes = 4;
 	if (!spi_mem_supports_op(nor->spimem, op)) {
-		if (nor->params->size > SZ_16M)
+		if (params->size > SZ_16M)
 			return -EOPNOTSUPP;
 
 		/* If flash size <= 16MB, 3 address bytes are sufficient */
@@ -1975,7 +1992,7 @@ static int spi_nor_spimem_check_pp(struct spi_nor *nor,
 static void
 spi_nor_spimem_adjust_hwcaps(struct spi_nor *nor, u32 *hwcaps)
 {
-	struct spi_nor_flash_parameter *params = nor->params;
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
 	unsigned int cap;
 
 	/* X-X-X modes are not supported yet, mask them all. */
@@ -2076,6 +2093,7 @@ static int spi_nor_select_read(struct spi_nor *nor,
 			       u32 shared_hwcaps)
 {
 	int cmd, best_match = fls(shared_hwcaps & SNOR_HWCAPS_READ_MASK) - 1;
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
 	const struct spi_nor_read_command *read;
 
 	if (best_match < 0)
@@ -2085,7 +2103,7 @@ static int spi_nor_select_read(struct spi_nor *nor,
 	if (cmd < 0)
 		return -EINVAL;
 
-	read = &nor->params->reads[cmd];
+	read = &params->reads[cmd];
 	nor->read_opcode = read->opcode;
 	nor->read_proto = read->proto;
 
@@ -2106,6 +2124,7 @@ static int spi_nor_select_read(struct spi_nor *nor,
 static int spi_nor_select_pp(struct spi_nor *nor,
 			     u32 shared_hwcaps)
 {
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
 	int cmd, best_match = fls(shared_hwcaps & SNOR_HWCAPS_PP_MASK) - 1;
 	const struct spi_nor_pp_command *pp;
 
@@ -2116,7 +2135,7 @@ static int spi_nor_select_pp(struct spi_nor *nor,
 	if (cmd < 0)
 		return -EINVAL;
 
-	pp = &nor->params->page_programs[cmd];
+	pp = &params->page_programs[cmd];
 	nor->program_opcode = pp->opcode;
 	nor->write_proto = pp->proto;
 	return 0;
@@ -2185,7 +2204,8 @@ spi_nor_select_uniform_erase(struct spi_nor_erase_map *map,
 
 static int spi_nor_select_erase(struct spi_nor *nor)
 {
-	struct spi_nor_erase_map *map = &nor->params->erase_map;
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
+	struct spi_nor_erase_map *map = &params->erase_map;
 	const struct spi_nor_erase_type *erase = NULL;
 	struct mtd_info *mtd = &nor->mtd;
 	u32 wanted_size = nor->info->sector_size;
@@ -2234,7 +2254,7 @@ static int spi_nor_select_erase(struct spi_nor *nor)
 static int spi_nor_default_setup(struct spi_nor *nor,
 				 const struct spi_nor_hwcaps *hwcaps)
 {
-	struct spi_nor_flash_parameter *params = nor->params;
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
 	u32 ignored_mask, shared_mask;
 	int err;
 
@@ -2294,8 +2314,10 @@ static int spi_nor_default_setup(struct spi_nor *nor,
 
 static int spi_nor_set_addr_nbytes(struct spi_nor *nor)
 {
-	if (nor->params->addr_nbytes) {
-		nor->addr_nbytes = nor->params->addr_nbytes;
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
+
+	if (params->addr_nbytes) {
+		nor->addr_nbytes = params->addr_nbytes;
 	} else if (nor->read_proto == SNOR_PROTO_8_8_8_DTR) {
 		/*
 		 * In 8D-8D-8D mode, one byte takes half a cycle to transfer. So
@@ -2316,7 +2338,7 @@ static int spi_nor_set_addr_nbytes(struct spi_nor *nor)
 		nor->addr_nbytes = 3;
 	}
 
-	if (nor->addr_nbytes == 3 && nor->params->size > 0x1000000) {
+	if (nor->addr_nbytes == 3 && params->size > 0x1000000) {
 		/* enable 4-byte addressing if the device exceeds 16MiB */
 		nor->addr_nbytes = 4;
 	}
@@ -2338,10 +2360,11 @@ static int spi_nor_set_addr_nbytes(struct spi_nor *nor)
 static int spi_nor_setup(struct spi_nor *nor,
 			 const struct spi_nor_hwcaps *hwcaps)
 {
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
 	int ret;
 
-	if (nor->params->setup)
-		ret = nor->params->setup(nor, hwcaps);
+	if (params->setup)
+		ret = params->setup(nor, hwcaps);
 	else
 		ret = spi_nor_default_setup(nor, hwcaps);
 	if (ret)
@@ -2376,7 +2399,7 @@ static void spi_nor_manufacturer_init_params(struct spi_nor *nor)
  */
 static void spi_nor_no_sfdp_init_params(struct spi_nor *nor)
 {
-	struct spi_nor_flash_parameter *params = nor->params;
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
 	struct spi_nor_erase_map *map = &params->erase_map;
 	const u8 no_sfdp_flags = nor->info->no_sfdp_flags;
 	u8 i, erase_mask;
@@ -2501,6 +2524,8 @@ static void spi_nor_init_fixup_flags(struct spi_nor *nor)
  */
 static void spi_nor_late_init_params(struct spi_nor *nor)
 {
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
+
 	if (nor->manufacturer && nor->manufacturer->fixups &&
 	    nor->manufacturer->fixups->late_init)
 		nor->manufacturer->fixups->late_init(nor);
@@ -2515,7 +2540,7 @@ static void spi_nor_late_init_params(struct spi_nor *nor)
 	 * NOR protection support. When locking_ops are not provided, we pick
 	 * the default ones.
 	 */
-	if (nor->flags & SNOR_F_HAS_LOCK && !nor->params->locking_ops)
+	if (nor->flags & SNOR_F_HAS_LOCK && !params->locking_ops)
 		spi_nor_init_default_locking_ops(nor);
 }
 
@@ -2529,12 +2554,13 @@ static void spi_nor_late_init_params(struct spi_nor *nor)
  */
 static void spi_nor_sfdp_init_params_deprecated(struct spi_nor *nor)
 {
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
 	struct spi_nor_flash_parameter sfdp_params;
 
-	memcpy(&sfdp_params, nor->params, sizeof(sfdp_params));
+	memcpy(&sfdp_params, params, sizeof(sfdp_params));
 
 	if (spi_nor_parse_sfdp(nor)) {
-		memcpy(nor->params, &sfdp_params, sizeof(*nor->params));
+		memcpy(params, &sfdp_params, sizeof(*params));
 		nor->flags &= ~SNOR_F_4B_OPCODES;
 	}
 }
@@ -2569,7 +2595,7 @@ static void spi_nor_init_params_deprecated(struct spi_nor *nor)
  */
 static void spi_nor_init_default_params(struct spi_nor *nor)
 {
-	struct spi_nor_flash_parameter *params = nor->params;
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
 	const struct flash_info *info = nor->info;
 	struct device_node *np = spi_nor_get_flash_node(nor);
 
@@ -2655,12 +2681,15 @@ static void spi_nor_init_default_params(struct spi_nor *nor)
  */
 static int spi_nor_init_params(struct spi_nor *nor)
 {
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
 	int ret;
 
-	nor->params = devm_kzalloc(nor->dev, sizeof(*nor->params), GFP_KERNEL);
-	if (!nor->params)
+	params = devm_kzalloc(nor->dev, sizeof(*params), GFP_KERNEL);
+	if (!params)
 		return -ENOMEM;
 
+	spi_nor_set_params(nor, 0, params);
+
 	spi_nor_init_default_params(nor);
 
 	if (nor->info->parse_sfdp) {
@@ -2688,9 +2717,10 @@ static int spi_nor_init_params(struct spi_nor *nor)
  */
 static int spi_nor_octal_dtr_enable(struct spi_nor *nor, bool enable)
 {
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
 	int ret;
 
-	if (!nor->params->octal_dtr_enable)
+	if (!params->octal_dtr_enable)
 		return 0;
 
 	if (!(nor->read_proto == SNOR_PROTO_8_8_8_DTR &&
@@ -2700,7 +2730,7 @@ static int spi_nor_octal_dtr_enable(struct spi_nor *nor, bool enable)
 	if (!(nor->flags & SNOR_F_IO_MODE_EN_VOLATILE))
 		return 0;
 
-	ret = nor->params->octal_dtr_enable(nor, enable);
+	ret = params->octal_dtr_enable(nor, enable);
 	if (ret)
 		return ret;
 
@@ -2720,18 +2750,21 @@ static int spi_nor_octal_dtr_enable(struct spi_nor *nor, bool enable)
  */
 static int spi_nor_quad_enable(struct spi_nor *nor)
 {
-	if (!nor->params->quad_enable)
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
+
+	if (!params->quad_enable)
 		return 0;
 
 	if (!(spi_nor_get_protocol_width(nor->read_proto) == 4 ||
 	      spi_nor_get_protocol_width(nor->write_proto) == 4))
 		return 0;
 
-	return nor->params->quad_enable(nor);
+	return params->quad_enable(nor);
 }
 
 static int spi_nor_init(struct spi_nor *nor)
 {
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
 	int err;
 
 	err = spi_nor_octal_dtr_enable(nor, true);
@@ -2773,7 +2806,7 @@ static int spi_nor_init(struct spi_nor *nor)
 		 */
 		WARN_ONCE(nor->flags & SNOR_F_BROKEN_RESET,
 			  "enabling reset hack; may not recover from unexpected reboots\n");
-		err = nor->params->set_4byte_addr_mode(nor, true);
+		err = params->set_4byte_addr_mode(nor, true);
 		if (err && err != -ENOTSUPP)
 			return err;
 	}
@@ -2889,12 +2922,14 @@ static void spi_nor_put_device(struct mtd_info *mtd)
 
 void spi_nor_restore(struct spi_nor *nor)
 {
+	struct spi_nor_flash_parameter *params;
 	int ret;
 
 	/* restore the addressing mode */
 	if (nor->addr_nbytes == 4 && !(nor->flags & SNOR_F_4B_OPCODES) &&
 	    nor->flags & SNOR_F_BROKEN_RESET) {
-		ret = nor->params->set_4byte_addr_mode(nor, false);
+		params = spi_nor_get_params(nor, 0);
+		ret = params->set_4byte_addr_mode(nor, false);
 		if (ret)
 			/*
 			 * Do not stop the execution in the hope that the flash
@@ -2966,6 +3001,7 @@ static const struct flash_info *spi_nor_get_flash_info(struct spi_nor *nor,
 
 static void spi_nor_set_mtd_info(struct spi_nor *nor)
 {
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
 	struct mtd_info *mtd = &nor->mtd;
 	struct device *dev = nor->dev;
 
@@ -2981,9 +3017,9 @@ static void spi_nor_set_mtd_info(struct spi_nor *nor)
 		mtd->flags |= MTD_NO_ERASE;
 	else
 		mtd->_erase = spi_nor_erase;
-	mtd->writesize = nor->params->writesize;
-	mtd->writebufsize = nor->params->page_size;
-	mtd->size = nor->params->size;
+	mtd->writesize = params->writesize;
+	mtd->writebufsize = params->page_size;
+	mtd->size = params->size;
 	mtd->_read = spi_nor_read;
 	/* Might be already set by some SST flashes. */
 	if (!mtd->_write)
@@ -3037,7 +3073,7 @@ int spi_nor_scan(struct spi_nor *nor, const char *name,
 	 * We need the bounce buffer early to read/write registers when going
 	 * through the spi-mem layer (buffers have to be DMA-able).
 	 * For spi-mem drivers, we'll reallocate a new buffer if
-	 * nor->params->page_size turns out to be greater than PAGE_SIZE (which
+	 * params->page_size turns out to be greater than PAGE_SIZE (which
 	 * shouldn't happen before long since NOR pages are usually less
 	 * than 1KB) after spi_nor_scan() returns.
 	 */
@@ -3108,13 +3144,14 @@ EXPORT_SYMBOL_GPL(spi_nor_scan);
 
 static int spi_nor_create_read_dirmap(struct spi_nor *nor)
 {
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
 	struct spi_mem_dirmap_info info = {
 		.op_tmpl = SPI_MEM_OP(SPI_MEM_OP_CMD(nor->read_opcode, 0),
 				      SPI_MEM_OP_ADDR(nor->addr_nbytes, 0, 0),
 				      SPI_MEM_OP_DUMMY(nor->read_dummy, 0),
 				      SPI_MEM_OP_DATA_IN(0, NULL, 0)),
 		.offset = 0,
-		.length = nor->params->size,
+		.length = params->size,
 	};
 	struct spi_mem_op *op = &info.op_tmpl;
 
@@ -3139,13 +3176,14 @@ static int spi_nor_create_read_dirmap(struct spi_nor *nor)
 
 static int spi_nor_create_write_dirmap(struct spi_nor *nor)
 {
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
 	struct spi_mem_dirmap_info info = {
 		.op_tmpl = SPI_MEM_OP(SPI_MEM_OP_CMD(nor->program_opcode, 0),
 				      SPI_MEM_OP_ADDR(nor->addr_nbytes, 0, 0),
 				      SPI_MEM_OP_NO_DUMMY,
 				      SPI_MEM_OP_DATA_OUT(0, NULL, 0)),
 		.offset = 0,
-		.length = nor->params->size,
+		.length = params->size,
 	};
 	struct spi_mem_op *op = &info.op_tmpl;
 
@@ -3168,6 +3206,7 @@ static int spi_nor_create_write_dirmap(struct spi_nor *nor)
 
 static int spi_nor_probe(struct spi_mem *spimem)
 {
+	struct spi_nor_flash_parameter *params;
 	struct spi_device *spi = spimem->spi;
 	struct flash_platform_data *data = dev_get_platdata(&spi->dev);
 	struct spi_nor *nor;
@@ -3214,13 +3253,15 @@ static int spi_nor_probe(struct spi_mem *spimem)
 
 	spi_nor_debugfs_register(nor);
 
+	params = spi_nor_get_params(nor, 0);
+
 	/*
 	 * None of the existing parts have > 512B pages, but let's play safe
 	 * and add this logic so that if anyone ever adds support for such
 	 * a NOR we don't end up with buffer overflows.
 	 */
-	if (nor->params->page_size > PAGE_SIZE) {
-		nor->bouncebuf_size = nor->params->page_size;
+	if (params->page_size > PAGE_SIZE) {
+		nor->bouncebuf_size = params->page_size;
 		devm_kfree(nor->dev, nor->bouncebuf);
 		nor->bouncebuf = devm_kmalloc(nor->dev,
 					      nor->bouncebuf_size,
diff --git a/drivers/mtd/spi-nor/debugfs.c b/drivers/mtd/spi-nor/debugfs.c
index 845b78c7ecc7..1ba86fc6166a 100644
--- a/drivers/mtd/spi-nor/debugfs.c
+++ b/drivers/mtd/spi-nor/debugfs.c
@@ -73,7 +73,7 @@ static void spi_nor_print_flags(struct seq_file *s, unsigned long flags,
 static int spi_nor_params_show(struct seq_file *s, void *data)
 {
 	struct spi_nor *nor = s->private;
-	struct spi_nor_flash_parameter *params = nor->params;
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
 	struct spi_nor_erase_map *erase_map = &params->erase_map;
 	struct spi_nor_erase_region *region;
 	const struct flash_info *info = nor->info;
@@ -181,7 +181,7 @@ static void spi_nor_print_pp_cmd(struct seq_file *s,
 static int spi_nor_capabilities_show(struct seq_file *s, void *data)
 {
 	struct spi_nor *nor = s->private;
-	struct spi_nor_flash_parameter *params = nor->params;
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
 	u32 hwcaps = params->hwcaps.mask;
 	int i, cmd;
 
diff --git a/drivers/mtd/spi-nor/gigadevice.c b/drivers/mtd/spi-nor/gigadevice.c
index d57ddaf1525b..643f131d3916 100644
--- a/drivers/mtd/spi-nor/gigadevice.c
+++ b/drivers/mtd/spi-nor/gigadevice.c
@@ -13,6 +13,8 @@ gd25q256_post_bfpt(struct spi_nor *nor,
 		   const struct sfdp_parameter_header *bfpt_header,
 		   const struct sfdp_bfpt *bfpt)
 {
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
+
 	/*
 	 * GD25Q256C supports the first version of JESD216 which does not define
 	 * the Quad Enable methods. Overwrite the default Quad Enable method.
@@ -24,7 +26,7 @@ gd25q256_post_bfpt(struct spi_nor *nor,
 	 */
 	if (bfpt_header->major == SFDP_JESD216_MAJOR &&
 	    bfpt_header->minor == SFDP_JESD216_MINOR)
-		nor->params->quad_enable = spi_nor_sr1_bit6_quad_enable;
+		params->quad_enable = spi_nor_sr1_bit6_quad_enable;
 
 	return 0;
 }
diff --git a/drivers/mtd/spi-nor/issi.c b/drivers/mtd/spi-nor/issi.c
index 400e2b42f45a..7785ba347526 100644
--- a/drivers/mtd/spi-nor/issi.c
+++ b/drivers/mtd/spi-nor/issi.c
@@ -13,6 +13,8 @@ is25lp256_post_bfpt_fixups(struct spi_nor *nor,
 			   const struct sfdp_parameter_header *bfpt_header,
 			   const struct sfdp_bfpt *bfpt)
 {
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
+
 	/*
 	 * IS25LP256 supports 4B opcodes, but the BFPT advertises
 	 * BFPT_DWORD1_ADDRESS_BYTES_3_ONLY.
@@ -20,7 +22,7 @@ is25lp256_post_bfpt_fixups(struct spi_nor *nor,
 	 */
 	if ((bfpt->dwords[SFDP_DWORD(1)] & BFPT_DWORD1_ADDRESS_BYTES_MASK) ==
 		BFPT_DWORD1_ADDRESS_BYTES_3_ONLY)
-		nor->params->addr_nbytes = 4;
+		params->addr_nbytes = 4;
 
 	return 0;
 }
@@ -31,7 +33,8 @@ static const struct spi_nor_fixups is25lp256_fixups = {
 
 static void pm25lv_nor_late_init(struct spi_nor *nor)
 {
-	struct spi_nor_erase_map *map = &nor->params->erase_map;
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
+	struct spi_nor_erase_map *map = &params->erase_map;
 	int i;
 
 	/* The PM25LV series has a different 4k sector erase opcode */
@@ -91,7 +94,9 @@ static const struct flash_info issi_nor_parts[] = {
 
 static void issi_nor_default_init(struct spi_nor *nor)
 {
-	nor->params->quad_enable = spi_nor_sr1_bit6_quad_enable;
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
+
+	params->quad_enable = spi_nor_sr1_bit6_quad_enable;
 }
 
 static const struct spi_nor_fixups issi_fixups = {
diff --git a/drivers/mtd/spi-nor/macronix.c b/drivers/mtd/spi-nor/macronix.c
index 6853ec9ae65d..85d3f5b04f74 100644
--- a/drivers/mtd/spi-nor/macronix.c
+++ b/drivers/mtd/spi-nor/macronix.c
@@ -104,8 +104,10 @@ static const struct flash_info macronix_nor_parts[] = {
 
 static void macronix_nor_default_init(struct spi_nor *nor)
 {
-	nor->params->quad_enable = spi_nor_sr1_bit6_quad_enable;
-	nor->params->set_4byte_addr_mode = spi_nor_set_4byte_addr_mode;
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
+
+	params->quad_enable = spi_nor_sr1_bit6_quad_enable;
+	params->set_4byte_addr_mode = spi_nor_set_4byte_addr_mode;
 }
 
 static const struct spi_nor_fixups macronix_nor_fixups = {
diff --git a/drivers/mtd/spi-nor/micron-st.c b/drivers/mtd/spi-nor/micron-st.c
index 7bb86df52f0b..b93e16094b6c 100644
--- a/drivers/mtd/spi-nor/micron-st.c
+++ b/drivers/mtd/spi-nor/micron-st.c
@@ -49,10 +49,11 @@
 
 static int micron_st_nor_octal_dtr_en(struct spi_nor *nor)
 {
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
 	struct spi_mem_op op;
 	u8 *buf = nor->bouncebuf;
 	int ret;
-	u8 addr_mode_nbytes = nor->params->addr_mode_nbytes;
+	u8 addr_mode_nbytes = params->addr_mode_nbytes;
 
 	/* Use 20 dummy cycles for memory array reads. */
 	*buf = 20;
@@ -128,27 +129,31 @@ static int micron_st_nor_octal_dtr_enable(struct spi_nor *nor, bool enable)
 
 static void mt35xu512aba_default_init(struct spi_nor *nor)
 {
-	nor->params->octal_dtr_enable = micron_st_nor_octal_dtr_enable;
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
+
+	params->octal_dtr_enable = micron_st_nor_octal_dtr_enable;
 }
 
 static void mt35xu512aba_post_sfdp_fixup(struct spi_nor *nor)
 {
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
+
 	/* Set the Fast Read settings. */
-	nor->params->hwcaps.mask |= SNOR_HWCAPS_READ_8_8_8_DTR;
-	spi_nor_set_read_settings(&nor->params->reads[SNOR_CMD_READ_8_8_8_DTR],
+	params->hwcaps.mask |= SNOR_HWCAPS_READ_8_8_8_DTR;
+	spi_nor_set_read_settings(&params->reads[SNOR_CMD_READ_8_8_8_DTR],
 				  0, 20, SPINOR_OP_MT_DTR_RD,
 				  SNOR_PROTO_8_8_8_DTR);
 
 	nor->cmd_ext_type = SPI_NOR_EXT_REPEAT;
-	nor->params->rdsr_dummy = 8;
-	nor->params->rdsr_addr_nbytes = 0;
+	params->rdsr_dummy = 8;
+	params->rdsr_addr_nbytes = 0;
 
 	/*
 	 * The BFPT quad enable field is set to a reserved value so the quad
 	 * enable function is ignored by spi_nor_parse_bfpt(). Make sure we
 	 * disable it.
 	 */
-	nor->params->quad_enable = NULL;
+	params->quad_enable = NULL;
 }
 
 static const struct spi_nor_fixups mt35xu512aba_fixups = {
@@ -336,14 +341,15 @@ static int micron_st_nor_set_4byte_addr_mode(struct spi_nor *nor, bool enable)
  */
 static int micron_st_nor_read_fsr(struct spi_nor *nor, u8 *fsr)
 {
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
 	int ret;
 
 	if (nor->spimem) {
 		struct spi_mem_op op = MICRON_ST_RDFSR_OP(fsr);
 
 		if (nor->reg_proto == SNOR_PROTO_8_8_8_DTR) {
-			op.addr.nbytes = nor->params->rdsr_addr_nbytes;
-			op.dummy.nbytes = nor->params->rdsr_dummy;
+			op.addr.nbytes = params->rdsr_addr_nbytes;
+			op.dummy.nbytes = params->rdsr_dummy;
 			/*
 			 * We don't want to read only one byte in DTR mode. So,
 			 * read 2 and then discard the second byte.
@@ -446,16 +452,20 @@ static int micron_st_nor_ready(struct spi_nor *nor)
 
 static void micron_st_nor_default_init(struct spi_nor *nor)
 {
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
+
 	nor->flags |= SNOR_F_HAS_LOCK;
 	nor->flags &= ~SNOR_F_HAS_16BIT_SR;
-	nor->params->quad_enable = NULL;
-	nor->params->set_4byte_addr_mode = micron_st_nor_set_4byte_addr_mode;
+	params->quad_enable = NULL;
+	params->set_4byte_addr_mode = micron_st_nor_set_4byte_addr_mode;
 }
 
 static void micron_st_nor_late_init(struct spi_nor *nor)
 {
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
+
 	if (nor->info->mfr_flags & USE_FSR)
-		nor->params->ready = micron_st_nor_ready;
+		params->ready = micron_st_nor_ready;
 }
 
 static const struct spi_nor_fixups micron_st_nor_fixups = {
diff --git a/drivers/mtd/spi-nor/otp.c b/drivers/mtd/spi-nor/otp.c
index 3d75899de303..5b0319ea7f96 100644
--- a/drivers/mtd/spi-nor/otp.c
+++ b/drivers/mtd/spi-nor/otp.c
@@ -19,7 +19,9 @@
  */
 static inline unsigned int spi_nor_otp_region_len(struct spi_nor *nor)
 {
-	return nor->params->otp.org->len;
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
+
+	return params->otp.org->len;
 }
 
 /**
@@ -30,7 +32,9 @@ static inline unsigned int spi_nor_otp_region_len(struct spi_nor *nor)
  */
 static inline unsigned int spi_nor_otp_n_regions(struct spi_nor *nor)
 {
-	return nor->params->otp.org->n_regions;
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
+
+	return params->otp.org->n_regions;
 }
 
 /**
@@ -241,7 +245,8 @@ int spi_nor_otp_is_locked_sr2(struct spi_nor *nor, unsigned int region)
 
 static loff_t spi_nor_otp_region_start(const struct spi_nor *nor, unsigned int region)
 {
-	const struct spi_nor_otp_organization *org = nor->params->otp.org;
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
+	const struct spi_nor_otp_organization *org = params->otp.org;
 
 	return org->base + region * org->offset;
 }
@@ -266,7 +271,8 @@ static int spi_nor_mtd_otp_info(struct mtd_info *mtd, size_t len,
 				size_t *retlen, struct otp_info *buf)
 {
 	struct spi_nor *nor = mtd_to_spi_nor(mtd);
-	const struct spi_nor_otp_ops *ops = nor->params->otp.ops;
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
+	const struct spi_nor_otp_ops *ops = params->otp.ops;
 	unsigned int n_regions = spi_nor_otp_n_regions(nor);
 	unsigned int i;
 	int ret, locked;
@@ -303,7 +309,8 @@ static int spi_nor_mtd_otp_info(struct mtd_info *mtd, size_t len,
 static int spi_nor_mtd_otp_range_is_locked(struct spi_nor *nor, loff_t ofs,
 					   size_t len)
 {
-	const struct spi_nor_otp_ops *ops = nor->params->otp.ops;
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
+	const struct spi_nor_otp_ops *ops = params->otp.ops;
 	unsigned int region;
 	int locked;
 
@@ -328,7 +335,8 @@ static int spi_nor_mtd_otp_read_write(struct mtd_info *mtd, loff_t ofs,
 				      const u8 *buf, bool is_write)
 {
 	struct spi_nor *nor = mtd_to_spi_nor(mtd);
-	const struct spi_nor_otp_ops *ops = nor->params->otp.ops;
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
+	const struct spi_nor_otp_ops *ops = params->otp.ops;
 	const size_t rlen = spi_nor_otp_region_len(nor);
 	loff_t rstart, rofs;
 	unsigned int region;
@@ -414,7 +422,8 @@ static int spi_nor_mtd_otp_write(struct mtd_info *mtd, loff_t to, size_t len,
 static int spi_nor_mtd_otp_erase(struct mtd_info *mtd, loff_t from, size_t len)
 {
 	struct spi_nor *nor = mtd_to_spi_nor(mtd);
-	const struct spi_nor_otp_ops *ops = nor->params->otp.ops;
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
+	const struct spi_nor_otp_ops *ops = params->otp.ops;
 	const size_t rlen = spi_nor_otp_region_len(nor);
 	unsigned int region;
 	loff_t rstart;
@@ -467,7 +476,8 @@ static int spi_nor_mtd_otp_erase(struct mtd_info *mtd, loff_t from, size_t len)
 static int spi_nor_mtd_otp_lock(struct mtd_info *mtd, loff_t from, size_t len)
 {
 	struct spi_nor *nor = mtd_to_spi_nor(mtd);
-	const struct spi_nor_otp_ops *ops = nor->params->otp.ops;
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
+	const struct spi_nor_otp_ops *ops = params->otp.ops;
 	const size_t rlen = spi_nor_otp_region_len(nor);
 	unsigned int region;
 	int ret;
@@ -501,9 +511,10 @@ static int spi_nor_mtd_otp_lock(struct mtd_info *mtd, loff_t from, size_t len)
 
 void spi_nor_set_mtd_otp_ops(struct spi_nor *nor)
 {
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
 	struct mtd_info *mtd = &nor->mtd;
 
-	if (!nor->params->otp.ops)
+	if (!params->otp.ops)
 		return;
 
 	if (WARN_ON(!is_power_of_2(spi_nor_otp_region_len(nor))))
diff --git a/drivers/mtd/spi-nor/sfdp.c b/drivers/mtd/spi-nor/sfdp.c
index 298ab5e53a8c..da96d3d27cb4 100644
--- a/drivers/mtd/spi-nor/sfdp.c
+++ b/drivers/mtd/spi-nor/sfdp.c
@@ -431,7 +431,7 @@ static void spi_nor_regions_sort_erase_types(struct spi_nor_erase_map *map)
 static int spi_nor_parse_bfpt(struct spi_nor *nor,
 			      const struct sfdp_parameter_header *bfpt_header)
 {
-	struct spi_nor_flash_parameter *params = nor->params;
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
 	struct spi_nor_erase_map *map = &params->erase_map;
 	struct spi_nor_erase_type *erase_type = map->erase_type;
 	struct sfdp_bfpt bfpt;
@@ -645,6 +645,8 @@ static int spi_nor_parse_bfpt(struct spi_nor *nor,
  */
 static u8 spi_nor_smpt_addr_nbytes(const struct spi_nor *nor, const u32 settings)
 {
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
+
 	switch (settings & SMPT_CMD_ADDRESS_LEN_MASK) {
 	case SMPT_CMD_ADDRESS_LEN_0:
 		return 0;
@@ -654,7 +656,7 @@ static u8 spi_nor_smpt_addr_nbytes(const struct spi_nor *nor, const u32 settings
 		return 4;
 	case SMPT_CMD_ADDRESS_LEN_USE_CURRENT:
 	default:
-		return nor->params->addr_mode_nbytes;
+		return params->addr_mode_nbytes;
 	}
 }
 
@@ -806,7 +808,8 @@ spi_nor_region_check_overlay(struct spi_nor_erase_region *region,
 static int spi_nor_init_non_uniform_erase_map(struct spi_nor *nor,
 					      const u32 *smpt)
 {
-	struct spi_nor_erase_map *map = &nor->params->erase_map;
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
+	struct spi_nor_erase_map *map = &params->erase_map;
 	struct spi_nor_erase_type *erase = map->erase_type;
 	struct spi_nor_erase_region *region;
 	u64 offset;
@@ -894,6 +897,7 @@ static int spi_nor_init_non_uniform_erase_map(struct spi_nor *nor,
 static int spi_nor_parse_smpt(struct spi_nor *nor,
 			      const struct sfdp_parameter_header *smpt_header)
 {
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
 	const u32 *sector_map;
 	u32 *smpt;
 	size_t len;
@@ -924,7 +928,7 @@ static int spi_nor_parse_smpt(struct spi_nor *nor,
 	if (ret)
 		goto out;
 
-	spi_nor_regions_sort_erase_types(&nor->params->erase_map);
+	spi_nor_regions_sort_erase_types(&params->erase_map);
 	/* fall through */
 out:
 	kfree(smpt);
@@ -964,7 +968,7 @@ static int spi_nor_parse_4bait(struct spi_nor *nor,
 		{ 0u /* not used */,		BIT(11) },
 		{ 0u /* not used */,		BIT(12) },
 	};
-	struct spi_nor_flash_parameter *params = nor->params;
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
 	struct spi_nor_pp_command *params_pp = params->page_programs;
 	struct spi_nor_erase_map *map = &params->erase_map;
 	struct spi_nor_erase_type *erase_type = map->erase_type;
@@ -1127,6 +1131,7 @@ static int spi_nor_parse_4bait(struct spi_nor *nor,
 static int spi_nor_parse_profile1(struct spi_nor *nor,
 				  const struct sfdp_parameter_header *profile1_header)
 {
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
 	u32 *dwords, addr;
 	size_t len;
 	int ret;
@@ -1149,14 +1154,14 @@ static int spi_nor_parse_profile1(struct spi_nor *nor,
 
 	 /* Set the Read Status Register dummy cycles and dummy address bytes. */
 	if (dwords[SFDP_DWORD(1)] & PROFILE1_DWORD1_RDSR_DUMMY)
-		nor->params->rdsr_dummy = 8;
+		params->rdsr_dummy = 8;
 	else
-		nor->params->rdsr_dummy = 4;
+		params->rdsr_dummy = 4;
 
 	if (dwords[SFDP_DWORD(1)] & PROFILE1_DWORD1_RDSR_ADDR_BYTES)
-		nor->params->rdsr_addr_nbytes = 4;
+		params->rdsr_addr_nbytes = 4;
 	else
-		nor->params->rdsr_addr_nbytes = 0;
+		params->rdsr_addr_nbytes = 0;
 
 	/*
 	 * We don't know what speed the controller is running at. Find the
@@ -1185,8 +1190,8 @@ static int spi_nor_parse_profile1(struct spi_nor *nor,
 	dummy = round_up(dummy, 2);
 
 	/* Update the fast read settings. */
-	nor->params->hwcaps.mask |= SNOR_HWCAPS_READ_8_8_8_DTR;
-	spi_nor_set_read_settings(&nor->params->reads[SNOR_CMD_READ_8_8_8_DTR],
+	params->hwcaps.mask |= SNOR_HWCAPS_READ_8_8_8_DTR;
+	spi_nor_set_read_settings(&params->reads[SNOR_CMD_READ_8_8_8_DTR],
 				  0, dummy, opcode,
 				  SNOR_PROTO_8_8_8_DTR);
 
@@ -1194,7 +1199,7 @@ static int spi_nor_parse_profile1(struct spi_nor *nor,
 	 * Page Program is "Required Command" in the xSPI Profile 1.0. Update
 	 * the params->hwcaps.mask here.
 	 */
-	nor->params->hwcaps.mask |= SNOR_HWCAPS_PP_8_8_8_DTR;
+	params->hwcaps.mask |= SNOR_HWCAPS_PP_8_8_8_DTR;
 
 out:
 	kfree(dwords);
diff --git a/drivers/mtd/spi-nor/spansion.c b/drivers/mtd/spi-nor/spansion.c
index 12a256c0ef4c..fe3293c597c9 100644
--- a/drivers/mtd/spi-nor/spansion.c
+++ b/drivers/mtd/spi-nor/spansion.c
@@ -51,10 +51,11 @@
 
 static int cypress_nor_octal_dtr_en(struct spi_nor *nor)
 {
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
 	struct spi_mem_op op;
 	u8 *buf = nor->bouncebuf;
 	int ret;
-	u8 addr_mode_nbytes = nor->params->addr_mode_nbytes;
+	u8 addr_mode_nbytes = params->addr_mode_nbytes;
 
 	/* Use 24 dummy cycles for memory array reads. */
 	*buf = SPINOR_REG_CYPRESS_CFR2_MEMLAT_11_24;
@@ -141,8 +142,9 @@ static int cypress_nor_octal_dtr_dis(struct spi_nor *nor)
  */
 static int cypress_nor_quad_enable_volatile(struct spi_nor *nor)
 {
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
 	struct spi_mem_op op;
-	u8 addr_mode_nbytes = nor->params->addr_mode_nbytes;
+	u8 addr_mode_nbytes = params->addr_mode_nbytes;
 	u8 cfr1v_written;
 	int ret;
 
@@ -200,8 +202,9 @@ static int cypress_nor_quad_enable_volatile(struct spi_nor *nor)
  */
 static int cypress_nor_set_page_size(struct spi_nor *nor)
 {
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
 	struct spi_mem_op op =
-		CYPRESS_NOR_RD_ANY_REG_OP(nor->params->addr_mode_nbytes,
+		CYPRESS_NOR_RD_ANY_REG_OP(params->addr_mode_nbytes,
 					  SPINOR_REG_CYPRESS_CFR3V,
 					  nor->bouncebuf);
 	int ret;
@@ -211,9 +214,9 @@ static int cypress_nor_set_page_size(struct spi_nor *nor)
 		return ret;
 
 	if (nor->bouncebuf[0] & SPINOR_REG_CYPRESS_CFR3_PGSZ)
-		nor->params->page_size = 512;
+		params->page_size = 512;
 	else
-		nor->params->page_size = 256;
+		params->page_size = 256;
 
 	return 0;
 }
@@ -223,16 +226,19 @@ s25hx_t_post_bfpt_fixup(struct spi_nor *nor,
 			const struct sfdp_parameter_header *bfpt_header,
 			const struct sfdp_bfpt *bfpt)
 {
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
+
 	/* Replace Quad Enable with volatile version */
-	nor->params->quad_enable = cypress_nor_quad_enable_volatile;
+	params->quad_enable = cypress_nor_quad_enable_volatile;
 
 	return cypress_nor_set_page_size(nor);
 }
 
 static void s25hx_t_post_sfdp_fixup(struct spi_nor *nor)
 {
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
 	struct spi_nor_erase_type *erase_type =
-					nor->params->erase_map.erase_type;
+					params->erase_map.erase_type;
 	unsigned int i;
 
 	/*
@@ -255,7 +261,7 @@ static void s25hx_t_post_sfdp_fixup(struct spi_nor *nor)
 
 static void s25hx_t_late_init(struct spi_nor *nor)
 {
-	struct spi_nor_flash_parameter *params = nor->params;
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
 
 	/* Fast Read 4B requires mode cycles */
 	params->reads[SNOR_CMD_READ_FAST].num_mode_clocks = 8;
@@ -288,22 +294,24 @@ static int cypress_nor_octal_dtr_enable(struct spi_nor *nor, bool enable)
 
 static void s28hx_t_post_sfdp_fixup(struct spi_nor *nor)
 {
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
+
 	/*
 	 * On older versions of the flash the xSPI Profile 1.0 table has the
 	 * 8D-8D-8D Fast Read opcode as 0x00. But it actually should be 0xEE.
 	 */
-	if (nor->params->reads[SNOR_CMD_READ_8_8_8_DTR].opcode == 0)
-		nor->params->reads[SNOR_CMD_READ_8_8_8_DTR].opcode =
+	if (params->reads[SNOR_CMD_READ_8_8_8_DTR].opcode == 0)
+		params->reads[SNOR_CMD_READ_8_8_8_DTR].opcode =
 			SPINOR_OP_CYPRESS_RD_FAST;
 
 	/* This flash is also missing the 4-byte Page Program opcode bit. */
-	spi_nor_set_pp_settings(&nor->params->page_programs[SNOR_CMD_PP],
+	spi_nor_set_pp_settings(&params->page_programs[SNOR_CMD_PP],
 				SPINOR_OP_PP_4B, SNOR_PROTO_1_1_1);
 	/*
 	 * Since xSPI Page Program opcode is backward compatible with
 	 * Legacy SPI, use Legacy SPI opcode there as well.
 	 */
-	spi_nor_set_pp_settings(&nor->params->page_programs[SNOR_CMD_PP_8_8_8_DTR],
+	spi_nor_set_pp_settings(&params->page_programs[SNOR_CMD_PP_8_8_8_DTR],
 				SPINOR_OP_PP_4B, SNOR_PROTO_8_8_8_DTR);
 
 	/*
@@ -311,7 +319,7 @@ static void s28hx_t_post_sfdp_fixup(struct spi_nor *nor)
 	 * address bytes needed for Read Status Register command as 0 but the
 	 * actual value for that is 4.
 	 */
-	nor->params->rdsr_addr_nbytes = 4;
+	params->rdsr_addr_nbytes = 4;
 }
 
 static int s28hx_t_post_bfpt_fixup(struct spi_nor *nor,
@@ -323,8 +331,10 @@ static int s28hx_t_post_bfpt_fixup(struct spi_nor *nor,
 
 static void s28hx_t_late_init(struct spi_nor *nor)
 {
-	nor->params->octal_dtr_enable = cypress_nor_octal_dtr_enable;
-	nor->params->writesize = 16;
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
+
+	params->octal_dtr_enable = cypress_nor_octal_dtr_enable;
+	params->writesize = 16;
 }
 
 static const struct spi_nor_fixups s28hx_t_fixups = {
@@ -338,13 +348,15 @@ s25fs_s_nor_post_bfpt_fixups(struct spi_nor *nor,
 			     const struct sfdp_parameter_header *bfpt_header,
 			     const struct sfdp_bfpt *bfpt)
 {
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
+
 	/*
 	 * The S25FS-S chip family reports 512-byte pages in BFPT but
 	 * in reality the write buffer still wraps at the safe default
 	 * of 256 bytes.  Overwrite the page size advertised by BFPT
 	 * to get the writes working.
 	 */
-	nor->params->page_size = 256;
+	params->page_size = 256;
 
 	return 0;
 }
@@ -546,7 +558,9 @@ static int spansion_nor_sr_ready_and_clear(struct spi_nor *nor)
 
 static void spansion_nor_late_init(struct spi_nor *nor)
 {
-	if (nor->params->size > SZ_16M) {
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
+
+	if (params->size > SZ_16M) {
 		nor->flags |= SNOR_F_4B_OPCODES;
 		/* No small sector erase for 4-byte command set */
 		nor->erase_opcode = SPINOR_OP_SE;
@@ -554,7 +568,7 @@ static void spansion_nor_late_init(struct spi_nor *nor)
 	}
 
 	if (nor->info->mfr_flags & USE_CLSR)
-		nor->params->ready = spansion_nor_sr_ready_and_clear;
+		params->ready = spansion_nor_sr_ready_and_clear;
 }
 
 static const struct spi_nor_fixups spansion_nor_fixups = {
diff --git a/drivers/mtd/spi-nor/sst.c b/drivers/mtd/spi-nor/sst.c
index 63bcc97bf978..6b91a32804ad 100644
--- a/drivers/mtd/spi-nor/sst.c
+++ b/drivers/mtd/spi-nor/sst.c
@@ -20,10 +20,11 @@ static int sst26vf_nor_lock(struct spi_nor *nor, loff_t ofs, uint64_t len)
 
 static int sst26vf_nor_unlock(struct spi_nor *nor, loff_t ofs, uint64_t len)
 {
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
 	int ret;
 
 	/* We only support unlocking the entire flash array. */
-	if (ofs != 0 || len != nor->params->size)
+	if (ofs != 0 || len != params->size)
 		return -EINVAL;
 
 	ret = spi_nor_read_cr(nor, nor->bouncebuf);
@@ -51,7 +52,9 @@ static const struct spi_nor_locking_ops sst26vf_nor_locking_ops = {
 
 static void sst26vf_nor_late_init(struct spi_nor *nor)
 {
-	nor->params->locking_ops = &sst26vf_nor_locking_ops;
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
+
+	params->locking_ops = &sst26vf_nor_locking_ops;
 }
 
 static const struct spi_nor_fixups sst26vf_nor_fixups = {
diff --git a/drivers/mtd/spi-nor/swp.c b/drivers/mtd/spi-nor/swp.c
index 1f178313ba8f..88eaed2c40fe 100644
--- a/drivers/mtd/spi-nor/swp.c
+++ b/drivers/mtd/spi-nor/swp.c
@@ -340,11 +340,14 @@ static const struct spi_nor_locking_ops spi_nor_sr_locking_ops = {
 
 void spi_nor_init_default_locking_ops(struct spi_nor *nor)
 {
-	nor->params->locking_ops = &spi_nor_sr_locking_ops;
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
+
+	params->locking_ops = &spi_nor_sr_locking_ops;
 }
 
 static int spi_nor_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 {
+	struct spi_nor_flash_parameter *params;
 	struct spi_nor *nor = mtd_to_spi_nor(mtd);
 	int ret;
 
@@ -352,7 +355,8 @@ static int spi_nor_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 	if (ret)
 		return ret;
 
-	ret = nor->params->locking_ops->lock(nor, ofs, len);
+	params = spi_nor_get_params(nor, 0);
+	ret = params->locking_ops->lock(nor, ofs, len);
 
 	spi_nor_unlock_and_unprep(nor);
 	return ret;
@@ -360,6 +364,7 @@ static int spi_nor_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 
 static int spi_nor_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 {
+	struct spi_nor_flash_parameter *params;
 	struct spi_nor *nor = mtd_to_spi_nor(mtd);
 	int ret;
 
@@ -367,7 +372,8 @@ static int spi_nor_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 	if (ret)
 		return ret;
 
-	ret = nor->params->locking_ops->unlock(nor, ofs, len);
+	params = spi_nor_get_params(nor, 0);
+	ret = params->locking_ops->unlock(nor, ofs, len);
 
 	spi_nor_unlock_and_unprep(nor);
 	return ret;
@@ -375,6 +381,7 @@ static int spi_nor_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 
 static int spi_nor_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 {
+	struct spi_nor_flash_parameter *params;
 	struct spi_nor *nor = mtd_to_spi_nor(mtd);
 	int ret;
 
@@ -382,7 +389,8 @@ static int spi_nor_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 	if (ret)
 		return ret;
 
-	ret = nor->params->locking_ops->is_locked(nor, ofs, len);
+	params = spi_nor_get_params(nor, 0);
+	ret = params->locking_ops->is_locked(nor, ofs, len);
 
 	spi_nor_unlock_and_unprep(nor);
 	return ret;
@@ -402,6 +410,7 @@ static int spi_nor_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
  */
 void spi_nor_try_unlock_all(struct spi_nor *nor)
 {
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
 	int ret;
 
 	if (!(nor->flags & SNOR_F_HAS_LOCK))
@@ -409,16 +418,17 @@ void spi_nor_try_unlock_all(struct spi_nor *nor)
 
 	dev_dbg(nor->dev, "Unprotecting entire flash array\n");
 
-	ret = spi_nor_unlock(&nor->mtd, 0, nor->params->size);
+	ret = spi_nor_unlock(&nor->mtd, 0, params->size);
 	if (ret)
 		dev_dbg(nor->dev, "Failed to unlock the entire flash memory array\n");
 }
 
 void spi_nor_set_mtd_locking_ops(struct spi_nor *nor)
 {
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
 	struct mtd_info *mtd = &nor->mtd;
 
-	if (!nor->params->locking_ops)
+	if (!params->locking_ops)
 		return;
 
 	mtd->_lock = spi_nor_lock;
diff --git a/drivers/mtd/spi-nor/winbond.c b/drivers/mtd/spi-nor/winbond.c
index ca39acf4112c..ce321e40d2f4 100644
--- a/drivers/mtd/spi-nor/winbond.c
+++ b/drivers/mtd/spi-nor/winbond.c
@@ -218,13 +218,17 @@ static const struct spi_nor_otp_ops winbond_nor_otp_ops = {
 
 static void winbond_nor_default_init(struct spi_nor *nor)
 {
-	nor->params->set_4byte_addr_mode = winbond_nor_set_4byte_addr_mode;
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
+
+	params->set_4byte_addr_mode = winbond_nor_set_4byte_addr_mode;
 }
 
 static void winbond_nor_late_init(struct spi_nor *nor)
 {
-	if (nor->params->otp.org->n_regions)
-		nor->params->otp.ops = &winbond_nor_otp_ops;
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
+
+	if (params->otp.org->n_regions)
+		params->otp.ops = &winbond_nor_otp_ops;
 }
 
 static const struct spi_nor_fixups winbond_nor_fixups = {
diff --git a/drivers/mtd/spi-nor/xilinx.c b/drivers/mtd/spi-nor/xilinx.c
index 5723157739fc..6c5da0e0f9a4 100644
--- a/drivers/mtd/spi-nor/xilinx.c
+++ b/drivers/mtd/spi-nor/xilinx.c
@@ -55,7 +55,8 @@ static const struct flash_info xilinx_nor_parts[] = {
  */
 static u32 s3an_nor_convert_addr(struct spi_nor *nor, u32 addr)
 {
-	u32 page_size = nor->params->page_size;
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
+	u32 page_size = params->page_size;
 	u32 offset, page;
 
 	offset = addr % page_size;
@@ -115,6 +116,7 @@ static int xilinx_nor_sr_ready(struct spi_nor *nor)
 static int xilinx_nor_setup(struct spi_nor *nor,
 			    const struct spi_nor_hwcaps *hwcaps)
 {
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
 	u32 page_size;
 	int ret;
 
@@ -140,14 +142,14 @@ static int xilinx_nor_setup(struct spi_nor *nor,
 	 */
 	if (nor->bouncebuf[0] & XSR_PAGESIZE) {
 		/* Flash in Power of 2 mode */
-		page_size = (nor->params->page_size == 264) ? 256 : 512;
-		nor->params->page_size = page_size;
+		page_size = (params->page_size == 264) ? 256 : 512;
+		params->page_size = page_size;
 		nor->mtd.writebufsize = page_size;
-		nor->params->size = 8 * page_size * nor->info->n_sectors;
+		params->size = 8 * page_size * nor->info->n_sectors;
 		nor->mtd.erasesize = 8 * page_size;
 	} else {
 		/* Flash in Default addressing mode */
-		nor->params->convert_addr = s3an_nor_convert_addr;
+		params->convert_addr = s3an_nor_convert_addr;
 		nor->mtd.erasesize = nor->info->sector_size;
 	}
 
@@ -156,8 +158,10 @@ static int xilinx_nor_setup(struct spi_nor *nor,
 
 static void xilinx_nor_late_init(struct spi_nor *nor)
 {
-	nor->params->setup = xilinx_nor_setup;
-	nor->params->ready = xilinx_nor_sr_ready;
+	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
+
+	params->setup = xilinx_nor_setup;
+	params->ready = xilinx_nor_sr_ready;
 }
 
 static const struct spi_nor_fixups xilinx_nor_fixups = {
diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h
index a3f8cdca90c8..338b73125131 100644
--- a/include/linux/mtd/spi-nor.h
+++ b/include/linux/mtd/spi-nor.h
@@ -420,6 +420,16 @@ static inline struct device_node *spi_nor_get_flash_node(struct spi_nor *nor)
 	return mtd_get_of_node(&nor->mtd);
 }
 
+static inline struct spi_nor_flash_parameter *spi_nor_get_params(const struct spi_nor *nor, u8 idx)
+{
+	return nor->params;
+}
+
+static inline void spi_nor_set_params(struct spi_nor *nor, u8 idx,
+				      struct spi_nor_flash_parameter *params)
+{
+	nor->params = params;
+}
 /**
  * spi_nor_scan() - scan the SPI NOR
  * @nor:	the spi_nor structure
-- 
2.25.1

[PATCH V6 12/15] mtd: spi-nor: Add stacked memories support in spi-nor

[Amit Kumar Mahapatra]

Each flash that is connected in stacked mode should have a separate
parameter structure. So, the flash parameter member(*params) of the spi_nor
structure is changed to an array (*params[2]). The array is used to store
the parameters of each flash connected in stacked configuration.

The current implementation assumes that a maximum of two flashes are
connected in stacked mode and both the flashes are of same make but can
differ in sizes. So, except the sizes all other flash parameters of both
the flashes are identical.

SPI-NOR is not aware of the chip_select values, for any incoming request
SPI-NOR will decide the flash index with the help of individual flash size
and the configuration type (single/stacked). SPI-NOR will pass on the flash
index information to the SPI core & SPI driver by setting the appropriate
bit in nor->spimem->spi->cs_index_mask. For example, if nth bit of
nor->spimem->spi->cs_index_mask is set then the driver would
assert/de-assert spi->chip_slect[n].

Signed-off-by: Amit Kumar Mahapatra <amit.kumar-mahapatra@amd.com>
---
 drivers/mtd/spi-nor/core.c  | 282 +++++++++++++++++++++++++++++-------
 drivers/mtd/spi-nor/core.h  |   4 +
 include/linux/mtd/spi-nor.h |  12 +-
 3 files changed, 244 insertions(+), 54 deletions(-)

diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c
index 66b6934b4465..0bc6b42f276c 100644
--- a/drivers/mtd/spi-nor/core.c
+++ b/drivers/mtd/spi-nor/core.c
@@ -1441,13 +1441,18 @@ static int spi_nor_erase_multi_sectors(struct spi_nor *nor, u64 addr, u32 len)
 static int spi_nor_erase(struct mtd_info *mtd, struct erase_info *instr)
 {
 	struct spi_nor *nor = mtd_to_spi_nor(mtd);
-	u32 addr, len;
+	struct spi_nor_flash_parameter *params;
+	u32 addr, len, offset, cur_cs_num = 0;
 	uint32_t rem;
 	int ret;
+	u64 sz;
 
 	dev_dbg(nor->dev, "at 0x%llx, len %lld\n", (long long)instr->addr,
 			(long long)instr->len);
 
+	params = spi_nor_get_params(nor, 0);
+	sz = params->size;
+
 	if (spi_nor_has_uniform_erase(nor)) {
 		div_u64_rem(instr->len, mtd->erasesize, &rem);
 		if (rem)
@@ -1465,26 +1470,30 @@ static int spi_nor_erase(struct mtd_info *mtd, struct erase_info *instr)
 	if (len == mtd->size && !(nor->flags & SNOR_F_NO_OP_CHIP_ERASE)) {
 		unsigned long timeout;
 
-		ret = spi_nor_write_enable(nor);
-		if (ret)
-			goto erase_err;
+		while (cur_cs_num < SNOR_FLASH_CNT_MAX && params) {
+			nor->spimem->spi->cs_index_mask = 0x01 << cur_cs_num;
+			ret = spi_nor_write_enable(nor);
+			if (ret)
+				goto erase_err;
 
-		ret = spi_nor_erase_chip(nor);
-		if (ret)
-			goto erase_err;
+			ret = spi_nor_erase_chip(nor);
+			if (ret)
+				goto erase_err;
 
-		/*
-		 * Scale the timeout linearly with the size of the flash, with
-		 * a minimum calibrated to an old 2MB flash. We could try to
-		 * pull these from CFI/SFDP, but these values should be good
-		 * enough for now.
-		 */
-		timeout = max(CHIP_ERASE_2MB_READY_WAIT_JIFFIES,
-			      CHIP_ERASE_2MB_READY_WAIT_JIFFIES *
-			      (unsigned long)(mtd->size / SZ_2M));
-		ret = spi_nor_wait_till_ready_with_timeout(nor, timeout);
-		if (ret)
-			goto erase_err;
+			/*
+			 * Scale the timeout linearly with the size of the flash, with
+			 * a minimum calibrated to an old 2MB flash. We could try to
+			 * pull these from CFI/SFDP, but these values should be good
+			 * enough for now.
+			 */
+			timeout = max(CHIP_ERASE_2MB_READY_WAIT_JIFFIES,
+				      CHIP_ERASE_2MB_READY_WAIT_JIFFIES *
+				      (unsigned long)(params->size / SZ_2M));
+			ret = spi_nor_wait_till_ready_with_timeout(nor, timeout);
+			if (ret)
+				goto erase_err;
+			cur_cs_num++;
+		}
 
 	/* REVISIT in some cases we could speed up erasing large regions
 	 * by using SPINOR_OP_SE instead of SPINOR_OP_BE_4K.  We may have set up
@@ -1493,12 +1502,26 @@ static int spi_nor_erase(struct mtd_info *mtd, struct erase_info *instr)
 
 	/* "sector"-at-a-time erase */
 	} else if (spi_nor_has_uniform_erase(nor)) {
+		/* Determine the flash from which the operation need to start */
+		while ((cur_cs_num < SNOR_FLASH_CNT_MAX) && (addr > sz - 1) && params) {
+			cur_cs_num++;
+			params = spi_nor_get_params(nor, cur_cs_num);
+			sz += params->size;
+		}
+
 		while (len) {
+			nor->spimem->spi->cs_index_mask = 0x01 << cur_cs_num;
 			ret = spi_nor_write_enable(nor);
 			if (ret)
 				goto erase_err;
 
-			ret = spi_nor_erase_sector(nor, addr);
+			offset = addr;
+			if (nor->flags & SNOR_F_HAS_STACKED) {
+				params = spi_nor_get_params(nor, cur_cs_num);
+				offset -= (sz - params->size);
+			}
+
+			ret = spi_nor_erase_sector(nor, offset);
 			if (ret)
 				goto erase_err;
 
@@ -1508,13 +1531,45 @@ static int spi_nor_erase(struct mtd_info *mtd, struct erase_info *instr)
 
 			addr += mtd->erasesize;
 			len -= mtd->erasesize;
+
+			/*
+			 * Flash cross over condition in stacked mode.
+			 */
+			if ((nor->flags & SNOR_F_HAS_STACKED) && (addr > sz - 1)) {
+				cur_cs_num++;
+				params = spi_nor_get_params(nor, cur_cs_num);
+				sz += params->size;
+			}
 		}
 
 	/* erase multiple sectors */
 	} else {
-		ret = spi_nor_erase_multi_sectors(nor, addr, len);
-		if (ret)
-			goto erase_err;
+		u64 erase_len = 0;
+
+		/* Determine the flash from which the operation need to start */
+		while ((cur_cs_num < SNOR_FLASH_CNT_MAX) && (addr > sz - 1) && params) {
+			cur_cs_num++;
+			params = spi_nor_get_params(nor, cur_cs_num);
+			sz += params->size;
+		}
+		/* perform multi sector erase onec per Flash*/
+		while (len) {
+			erase_len = (len > (sz - addr)) ? (sz - addr) : len;
+			offset = addr;
+			nor->spimem->spi->cs_index_mask = 0x01 << cur_cs_num;
+			if (nor->flags & SNOR_F_HAS_STACKED) {
+				params = spi_nor_get_params(nor, cur_cs_num);
+				offset -= (sz - params->size);
+			}
+			ret = spi_nor_erase_multi_sectors(nor, offset, erase_len);
+			if (ret)
+				goto erase_err;
+			len -= erase_len;
+			addr += erase_len;
+			cur_cs_num++;
+			params = spi_nor_get_params(nor, cur_cs_num);
+			sz += params->size;
+		}
 	}
 
 	ret = spi_nor_write_disable(nor);
@@ -1713,7 +1768,10 @@ static int spi_nor_read(struct mtd_info *mtd, loff_t from, size_t len,
 			size_t *retlen, u_char *buf)
 {
 	struct spi_nor *nor = mtd_to_spi_nor(mtd);
-	ssize_t ret;
+	struct spi_nor_flash_parameter *params;
+	ssize_t ret, read_len;
+	u32 cur_cs_num = 0;
+	u64 sz;
 
 	dev_dbg(nor->dev, "from 0x%08x, len %zd\n", (u32)from, len);
 
@@ -1721,9 +1779,23 @@ static int spi_nor_read(struct mtd_info *mtd, loff_t from, size_t len,
 	if (ret)
 		return ret;
 
+	params = spi_nor_get_params(nor, 0);
+	sz = params->size;
+
+	/* Determine the flash from which the operation need to start */
+	while ((cur_cs_num < SNOR_FLASH_CNT_MAX) && (from > sz - 1) && params) {
+		cur_cs_num++;
+		params = spi_nor_get_params(nor, cur_cs_num);
+		sz += params->size;
+	}
 	while (len) {
 		loff_t addr = from;
 
+		nor->spimem->spi->cs_index_mask = 0x01 << cur_cs_num;
+		read_len = (len > (sz - addr)) ? (sz - addr) : len;
+		params = spi_nor_get_params(nor, cur_cs_num);
+		addr -= (sz - params->size);
+
 		addr = spi_nor_convert_addr(nor, addr);
 
 		ret = spi_nor_read_data(nor, addr, len, buf);
@@ -1735,11 +1807,22 @@ static int spi_nor_read(struct mtd_info *mtd, loff_t from, size_t len,
 		if (ret < 0)
 			goto read_err;
 
-		WARN_ON(ret > len);
+		WARN_ON(ret > read_len);
 		*retlen += ret;
 		buf += ret;
 		from += ret;
 		len -= ret;
+
+		/*
+		 * Flash cross over condition in stacked mode.
+		 *
+		 */
+		if ((nor->flags & SNOR_F_HAS_STACKED) && (from > sz - 1)) {
+			cur_cs_num++;
+			params = spi_nor_get_params(nor, cur_cs_num);
+			sz += params->size;
+		}
+
 	}
 	ret = 0;
 
@@ -1759,13 +1842,22 @@ static int spi_nor_write(struct mtd_info *mtd, loff_t to, size_t len,
 	struct spi_nor *nor = mtd_to_spi_nor(mtd);
 	struct spi_nor_flash_parameter *params;
 	size_t page_offset, page_remain, i;
+	u32 page_size, cur_cs_num = 0;
 	ssize_t ret;
-	u32 page_size;
+	u64 sz;
 
 	dev_dbg(nor->dev, "to 0x%08x, len %zd\n", (u32)to, len);
 
 	params = spi_nor_get_params(nor, 0);
 	page_size = params->page_size;
+	sz = params->size;
+
+	/* Determine the flash from which the operation need to start */
+	while ((cur_cs_num < SNOR_FLASH_CNT_MAX) && (to > sz - 1) && params) {
+		cur_cs_num++;
+		params = spi_nor_get_params(nor, cur_cs_num);
+		sz += params->size;
+	}
 
 	ret = spi_nor_lock_and_prep(nor);
 	if (ret)
@@ -1790,6 +1882,10 @@ static int spi_nor_write(struct mtd_info *mtd, loff_t to, size_t len,
 		/* the size of data remaining on the first page */
 		page_remain = min_t(size_t, page_size - page_offset, len - i);
 
+		nor->spimem->spi->cs_index_mask = 0x01 << cur_cs_num;
+		params = spi_nor_get_params(nor, cur_cs_num);
+		addr -= (sz - params->size);
+
 		addr = spi_nor_convert_addr(nor, addr);
 
 		ret = spi_nor_write_enable(nor);
@@ -1806,6 +1902,15 @@ static int spi_nor_write(struct mtd_info *mtd, loff_t to, size_t len,
 			goto write_err;
 		*retlen += written;
 		i += written;
+
+		/*
+		 * Flash cross over condition in stacked mode.
+		 */
+		if ((nor->flags & SNOR_F_HAS_STACKED) && ((to + i) > sz - 1)) {
+			cur_cs_num++;
+			params = spi_nor_get_params(nor, cur_cs_num);
+			sz += params->size;
+		}
 	}
 
 write_err:
@@ -1918,8 +2023,6 @@ int spi_nor_hwcaps_pp2cmd(u32 hwcaps)
 static int spi_nor_spimem_check_op(struct spi_nor *nor,
 				   struct spi_mem_op *op)
 {
-	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
-
 	/*
 	 * First test with 4 address bytes. The opcode itself might
 	 * be a 3B addressing opcode but we don't care, because
@@ -1928,7 +2031,7 @@ static int spi_nor_spimem_check_op(struct spi_nor *nor,
 	 */
 	op->addr.nbytes = 4;
 	if (!spi_mem_supports_op(nor->spimem, op)) {
-		if (params->size > SZ_16M)
+		if (nor->mtd.size > SZ_16M)
 			return -EOPNOTSUPP;
 
 		/* If flash size <= 16MB, 3 address bytes are sufficient */
@@ -2525,6 +2628,10 @@ static void spi_nor_init_fixup_flags(struct spi_nor *nor)
 static void spi_nor_late_init_params(struct spi_nor *nor)
 {
 	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
+	struct device_node *np = spi_nor_get_flash_node(nor);
+	u64 flash_size[SNOR_FLASH_CNT_MAX];
+	u32 idx = 0, i = 0;
+	int rc;
 
 	if (nor->manufacturer && nor->manufacturer->fixups &&
 	    nor->manufacturer->fixups->late_init)
@@ -2542,6 +2649,36 @@ static void spi_nor_late_init_params(struct spi_nor *nor)
 	 */
 	if (nor->flags & SNOR_F_HAS_LOCK && !params->locking_ops)
 		spi_nor_init_default_locking_ops(nor);
+	/*
+	 * The flashes that are connected in stacked mode should be of same make.
+	 * Except the flash size all other properties are identical for all the
+	 * flashes connected in stacked mode.
+	 * The flashes that are connected in parallel mode should be identical.
+	 */
+	while (i < SNOR_FLASH_CNT_MAX) {
+		rc = of_property_read_u64_index(np, "stacked-memories", idx, &flash_size[i]);
+		if (rc == -EINVAL) {
+			break;
+		} else if (rc == -EOVERFLOW) {
+			idx++;
+		} else {
+			idx++;
+			i++;
+			if (!(nor->flags & SNOR_F_HAS_STACKED))
+				nor->flags |= SNOR_F_HAS_STACKED;
+		}
+	}
+	if (nor->flags & SNOR_F_HAS_STACKED) {
+		for (idx = 1; idx < SNOR_FLASH_CNT_MAX; idx++) {
+			params = spi_nor_get_params(nor, idx);
+			params = devm_kzalloc(nor->dev, sizeof(*params), GFP_KERNEL);
+			if (params) {
+				memcpy(params, spi_nor_get_params(nor, 0), sizeof(*params));
+				params->size = flash_size[idx];
+				spi_nor_set_params(nor, idx, params);
+			}
+		}
+	}
 }
 
 /**
@@ -2750,22 +2887,36 @@ static int spi_nor_octal_dtr_enable(struct spi_nor *nor, bool enable)
  */
 static int spi_nor_quad_enable(struct spi_nor *nor)
 {
-	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
+	struct spi_nor_flash_parameter *params;
+	int err, idx;
 
-	if (!params->quad_enable)
-		return 0;
+	for (idx = 0; idx < SNOR_FLASH_CNT_MAX; idx++) {
+		params = spi_nor_get_params(nor, idx);
+		if (params) {
+			if (!params->quad_enable)
+				return 0;
 
-	if (!(spi_nor_get_protocol_width(nor->read_proto) == 4 ||
-	      spi_nor_get_protocol_width(nor->write_proto) == 4))
-		return 0;
+			if (!(spi_nor_get_protocol_width(nor->read_proto) == 4 ||
+			      spi_nor_get_protocol_width(nor->write_proto) == 4))
+				return 0;
+			/*
+			 * Set the appropriate CS index before
+			 * issuing the command.
+			 */
+			nor->spimem->spi->cs_index_mask = 0x01 << idx;
 
-	return params->quad_enable(nor);
+			err = params->quad_enable(nor);
+			if (err)
+				return err;
+		}
+	}
+	return err;
 }
 
 static int spi_nor_init(struct spi_nor *nor)
 {
-	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
-	int err;
+	struct spi_nor_flash_parameter *params;
+	int err, idx;
 
 	err = spi_nor_octal_dtr_enable(nor, true);
 	if (err) {
@@ -2806,9 +2957,19 @@ static int spi_nor_init(struct spi_nor *nor)
 		 */
 		WARN_ONCE(nor->flags & SNOR_F_BROKEN_RESET,
 			  "enabling reset hack; may not recover from unexpected reboots\n");
-		err = params->set_4byte_addr_mode(nor, true);
-		if (err && err != -ENOTSUPP)
-			return err;
+		for (idx = 0; idx < SNOR_FLASH_CNT_MAX; idx++) {
+			params = spi_nor_get_params(nor, idx);
+			if (params) {
+				/*
+				 * Select the appropriate CS index before
+				 * issuing the command.
+				 */
+				nor->spimem->spi->cs_index_mask = 0x01 << idx;
+				err = params->set_4byte_addr_mode(nor, true);
+				if (err && err != -ENOTSUPP)
+					return err;
+			}
+		}
 	}
 
 	return 0;
@@ -2924,19 +3085,31 @@ void spi_nor_restore(struct spi_nor *nor)
 {
 	struct spi_nor_flash_parameter *params;
 	int ret;
+	int idx;
 
 	/* restore the addressing mode */
 	if (nor->addr_nbytes == 4 && !(nor->flags & SNOR_F_4B_OPCODES) &&
 	    nor->flags & SNOR_F_BROKEN_RESET) {
-		params = spi_nor_get_params(nor, 0);
-		ret = params->set_4byte_addr_mode(nor, false);
-		if (ret)
-			/*
-			 * Do not stop the execution in the hope that the flash
-			 * will default to the 3-byte address mode after the
-			 * software reset.
-			 */
-			dev_err(nor->dev, "Failed to exit 4-byte address mode, err = %d\n", ret);
+		for (idx = 0; idx < SNOR_FLASH_CNT_MAX; idx++) {
+			params = spi_nor_get_params(nor, idx);
+			if (params) {
+				/*
+				 * Select the appropriate CS index before
+				 * issuing the command.
+				 */
+				nor->spimem->spi->cs_index_mask = 0x01 << idx;
+				ret = params->set_4byte_addr_mode(nor, false);
+				if (ret)
+					/*
+					 * Do not stop the execution in the hope that the flash
+					 * will default to the 3-byte address mode after the
+					 * software reset.
+					 */
+					dev_err(nor->dev,
+						"Failed to exit 4-byte address mode, err = %d\n",
+						ret);
+			}
+		}
 	}
 
 	if (nor->flags & SNOR_F_SOFT_RESET)
@@ -3004,6 +3177,8 @@ static void spi_nor_set_mtd_info(struct spi_nor *nor)
 	struct spi_nor_flash_parameter *params = spi_nor_get_params(nor, 0);
 	struct mtd_info *mtd = &nor->mtd;
 	struct device *dev = nor->dev;
+	u64 total_sz = 0;
+	int idx;
 
 	spi_nor_set_mtd_locking_ops(nor);
 	spi_nor_set_mtd_otp_ops(nor);
@@ -3019,7 +3194,12 @@ static void spi_nor_set_mtd_info(struct spi_nor *nor)
 		mtd->_erase = spi_nor_erase;
 	mtd->writesize = params->writesize;
 	mtd->writebufsize = params->page_size;
-	mtd->size = params->size;
+	for (idx = 0; idx < SNOR_FLASH_CNT_MAX; idx++) {
+		params = spi_nor_get_params(nor, idx);
+		if (params)
+			total_sz += params->size;
+	}
+	mtd->size = total_sz;
 	mtd->_read = spi_nor_read;
 	/* Might be already set by some SST flashes. */
 	if (!mtd->_write)
diff --git a/drivers/mtd/spi-nor/core.h b/drivers/mtd/spi-nor/core.h
index 25423225c29d..cff2f9c389b8 100644
--- a/drivers/mtd/spi-nor/core.h
+++ b/drivers/mtd/spi-nor/core.h
@@ -11,6 +11,9 @@
 
 #define SPI_NOR_MAX_ID_LEN	6
 
+/* In single configuration enable CS0 */
+#define SPI_NOR_ENABLE_CS0     BIT(0)
+
 /* Standard SPI NOR flash operations. */
 #define SPI_NOR_READID_OP(naddr, ndummy, buf, len)			\
 	SPI_MEM_OP(SPI_MEM_OP_CMD(SPINOR_OP_RDID, 0),			\
@@ -130,6 +133,7 @@ enum spi_nor_option_flags {
 	SNOR_F_IO_MODE_EN_VOLATILE = BIT(11),
 	SNOR_F_SOFT_RESET	= BIT(12),
 	SNOR_F_SWP_IS_VOLATILE	= BIT(13),
+	SNOR_F_HAS_STACKED      = BIT(14),
 };
 
 struct spi_nor_read_command {
diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h
index 338b73125131..99f0f2ede444 100644
--- a/include/linux/mtd/spi-nor.h
+++ b/include/linux/mtd/spi-nor.h
@@ -127,6 +127,12 @@
 #define SR2_LB3			BIT(5)	/* Security Register Lock Bit 3 */
 #define SR2_QUAD_EN_BIT7	BIT(7)
 
+/*
+ * Maximum number of flashes that can be connected
+ * in stacked/parallel configuration
+ */
+#define	SNOR_FLASH_CNT_MAX	2
+
 /* Supported SPI protocols */
 #define SNOR_PROTO_INST_MASK	GENMASK(23, 16)
 #define SNOR_PROTO_INST_SHIFT	16
@@ -399,7 +405,7 @@ struct spi_nor {
 
 	const struct spi_nor_controller_ops *controller_ops;
 
-	struct spi_nor_flash_parameter *params;
+	struct spi_nor_flash_parameter *params[SNOR_FLASH_CNT_MAX];
 
 	struct {
 		struct spi_mem_dirmap_desc *rdesc;
@@ -422,13 +428,13 @@ static inline struct device_node *spi_nor_get_flash_node(struct spi_nor *nor)
 
 static inline struct spi_nor_flash_parameter *spi_nor_get_params(const struct spi_nor *nor, u8 idx)
 {
-	return nor->params;
+	return nor->params[idx];
 }
 
 static inline void spi_nor_set_params(struct spi_nor *nor, u8 idx,
 				      struct spi_nor_flash_parameter *params)
 {
-	nor->params = params;
+	nor->params[idx] = params;
 }
 /**
  * spi_nor_scan() - scan the SPI NOR
-- 
2.25.1

[PATCH V6 13/15] spi: spi-zynqmp-gqspi: Add stacked memories support in GQSPI driver

[Amit Kumar Mahapatra]

GQSPI supports two chip select CS0 & CS1. Update the driver to
assert/de-assert the appropriate chip select as per the bits set in
qspi->cs_index_mask.

Signed-off-by: Amit Kumar Mahapatra <amit.kumar-mahapatra@amd.com>
---
 drivers/spi/spi-zynqmp-gqspi.c | 21 +++++++++++++--------
 1 file changed, 13 insertions(+), 8 deletions(-)

diff --git a/drivers/spi/spi-zynqmp-gqspi.c b/drivers/spi/spi-zynqmp-gqspi.c
index fb2ca9b90eab..3d2b92a88e8a 100644
--- a/drivers/spi/spi-zynqmp-gqspi.c
+++ b/drivers/spi/spi-zynqmp-gqspi.c
@@ -156,6 +156,9 @@
 #define GQSPI_FREQ_100MHZ	100000000
 #define GQSPI_FREQ_150MHZ	150000000
 
+#define GQSPI_SELECT_LOWER_CS  BIT(0)
+#define GQSPI_SELECT_UPPER_CS  BIT(1)
+
 #define SPI_AUTOSUSPEND_TIMEOUT		3000
 enum mode_type {GQSPI_MODE_IO, GQSPI_MODE_DMA};
 
@@ -467,15 +470,17 @@ static void zynqmp_qspi_chipselect(struct spi_device *qspi, bool is_high)
 
 	genfifoentry |= GQSPI_GENFIFO_MODE_SPI;
 
+	if (qspi->cs_index_mask & GQSPI_SELECT_UPPER_CS) {
+		zynqmp_gqspi_selectslave(xqspi,
+					 GQSPI_SELECT_FLASH_CS_UPPER,
+					 GQSPI_SELECT_FLASH_BUS_LOWER);
+	} else if (qspi->cs_index_mask & GQSPI_SELECT_LOWER_CS) {
+		zynqmp_gqspi_selectslave(xqspi,
+					 GQSPI_SELECT_FLASH_CS_LOWER,
+					 GQSPI_SELECT_FLASH_BUS_LOWER);
+	}
+	genfifoentry |= xqspi->genfifobus;
 	if (!is_high) {
-		if (!spi_get_chipselect(qspi, 0)) {
-			xqspi->genfifobus = GQSPI_GENFIFO_BUS_LOWER;
-			xqspi->genfifocs = GQSPI_GENFIFO_CS_LOWER;
-		} else {
-			xqspi->genfifobus = GQSPI_GENFIFO_BUS_UPPER;
-			xqspi->genfifocs = GQSPI_GENFIFO_CS_UPPER;
-		}
-		genfifoentry |= xqspi->genfifobus;
 		genfifoentry |= xqspi->genfifocs;
 		genfifoentry |= GQSPI_GENFIFO_CS_SETUP;
 	} else {
-- 
2.25.1

[PATCH V6 14/15] mtd: spi-nor: Add parallel memories support in spi-nor

[Amit Kumar Mahapatra]

The current implementation assumes that a maximum of two flashes are
connected in parallel mode. The QSPI controller splits the data evenly
between both the flashes so, both the flashes that are connected in
parallel mode should be identical.
During each operation SPI-NOR sets 0th bit for CS0 & 1st bit for CS1 in
nor->spimem->spi->cs_index_mask. The QSPI driver will then assert/de-assert
CS0 & CS1.
Write operation in parallel mode are performed in page size * 2 chunks as
each write operation results in writing both the flashes. For doubling the
address space each operation is performed at addr/2 flash offset, where
addr is the address specified by the user.

Signed-off-by: Amit Kumar Mahapatra <amit.kumar-mahapatra@amd.com>
---
 drivers/mtd/spi-nor/core.c      | 514 +++++++++++++++++++++++---------
 drivers/mtd/spi-nor/core.h      |   4 +
 drivers/mtd/spi-nor/micron-st.c |   5 +
 3 files changed, 384 insertions(+), 139 deletions(-)

diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c
index 0bc6b42f276c..18fc4a1c28d4 100644
--- a/drivers/mtd/spi-nor/core.c
+++ b/drivers/mtd/spi-nor/core.c
@@ -464,17 +464,29 @@ int spi_nor_read_sr(struct spi_nor *nor, u8 *sr)
 			op.data.nbytes = 2;
 		}
 
+		if (nor->flags & SNOR_F_HAS_PARALLEL)
+			op.data.nbytes = 2;
+
 		spi_nor_spimem_setup_op(nor, &op, nor->reg_proto);
 
 		ret = spi_mem_exec_op(nor->spimem, &op);
 	} else {
-		ret = spi_nor_controller_ops_read_reg(nor, SPINOR_OP_RDSR, sr,
-						      1);
+		if (nor->flags & SNOR_F_HAS_PARALLEL)
+			ret = spi_nor_controller_ops_read_reg(nor,
+							      SPINOR_OP_RDSR,
+							      sr, 2);
+		else
+			ret = spi_nor_controller_ops_read_reg(nor,
+							      SPINOR_OP_RDSR,
+							      sr, 1);
 	}
 
 	if (ret)
 		dev_dbg(nor->dev, "error %d reading SR\n", ret);
 
+	if (nor->flags & SNOR_F_HAS_PARALLEL)
+		sr[0] |= sr[1];
+
 	return ret;
 }
 
@@ -1466,12 +1478,122 @@ static int spi_nor_erase(struct mtd_info *mtd, struct erase_info *instr)
 	if (ret)
 		return ret;
 
-	/* whole-chip erase? */
-	if (len == mtd->size && !(nor->flags & SNOR_F_NO_OP_CHIP_ERASE)) {
-		unsigned long timeout;
+	if (!(nor->flags & SNOR_F_HAS_PARALLEL)) {
+		/* whole-chip erase? */
+		if (len == mtd->size && !(nor->flags & SNOR_F_NO_OP_CHIP_ERASE)) {
+			unsigned long timeout;
+
+			while ((cur_cs_num < SNOR_FLASH_CNT_MAX) && params) {
+				nor->spimem->spi->cs_index_mask = 1 << cur_cs_num;
+				ret = spi_nor_write_enable(nor);
+				if (ret)
+					goto erase_err;
+
+				ret = spi_nor_erase_chip(nor);
+				if (ret)
+					goto erase_err;
+
+				/*
+				 * Scale the timeout linearly with the size of the flash, with
+				 * a minimum calibrated to an old 2MB flash. We could try to
+				 * pull these from CFI/SFDP, but these values should be good
+				 * enough for now.
+				 */
+				timeout = max(CHIP_ERASE_2MB_READY_WAIT_JIFFIES,
+					      CHIP_ERASE_2MB_READY_WAIT_JIFFIES *
+					      (unsigned long)(params->size /
+							      SZ_2M));
+				ret = spi_nor_wait_till_ready_with_timeout(nor, timeout);
+				if (ret)
+					goto erase_err;
+
+				cur_cs_num++;
+				params = spi_nor_get_params(nor, cur_cs_num);
+			}
+
+		/* REVISIT in some cases we could speed up erasing large regions
+		 * by using SPINOR_OP_SE instead of SPINOR_OP_BE_4K.  We may have set up
+		 * to use "small sector erase", but that's not always optimal.
+		 */
+
+		/* "sector"-at-a-time erase */
+		} else if (spi_nor_has_uniform_erase(nor)) {
+			/* Determine the flash from which the operation need to start */
+			while ((cur_cs_num < SNOR_FLASH_CNT_MAX) &&
+			       (addr > sz - 1) && params) {
+				cur_cs_num++;
+				params = spi_nor_get_params(nor, cur_cs_num);
+				sz += params->size;
+			}
+			while (len) {
+				nor->spimem->spi->cs_index_mask = 1 << cur_cs_num;
+				ret = spi_nor_write_enable(nor);
+				if (ret)
+					goto erase_err;
+
+				offset = addr;
+				if (nor->flags & SNOR_F_HAS_STACKED) {
+					params = spi_nor_get_params(nor, cur_cs_num);
+					offset -= (sz - params->size);
+				}
+				ret = spi_nor_erase_sector(nor, offset);
+				if (ret)
+					goto erase_err;
+
+				ret = spi_nor_wait_till_ready(nor);
+				if (ret)
+					goto erase_err;
+
+				addr += mtd->erasesize;
+				len -= mtd->erasesize;
+
+				/*
+				 * Flash cross over condition in stacked mode.
+				 */
+				if ((nor->flags & SNOR_F_HAS_STACKED) && (addr > sz - 1)) {
+					cur_cs_num++;
+					params = spi_nor_get_params(nor, cur_cs_num);
+					sz += params->size;
+				}
+			}
+
+		/* erase multiple sectors */
+		} else {
+			u64 erase_len = 0;
+
+			/* Determine the flash from which the operation need to start */
+			while ((cur_cs_num < SNOR_FLASH_CNT_MAX) &&
+			       (addr > sz - 1) && params) {
+				cur_cs_num++;
+				params = spi_nor_get_params(nor, cur_cs_num);
+				sz += params->size;
+			}
+			/* perform multi sector erase onec per Flash*/
+			while (len) {
+				erase_len = (len > (sz - addr)) ? (sz - addr) : len;
+				offset = addr;
+				nor->spimem->spi->cs_index_mask = 1 << cur_cs_num;
+				if (nor->flags & SNOR_F_HAS_STACKED) {
+					params = spi_nor_get_params(nor, cur_cs_num);
+					offset -= (sz - params->size);
+				}
+				ret = spi_nor_erase_multi_sectors(nor, offset, erase_len);
+				if (ret)
+					goto erase_err;
+				len -= erase_len;
+				addr += erase_len;
+				params = spi_nor_get_params(nor, cur_cs_num);
+				sz += params->size;
+			}
+		}
+	} else {
+		nor->spimem->spi->cs_index_mask = SPI_NOR_ENABLE_MULTI_CS;
+
+		/* whole-chip erase? */
+		if (len == mtd->size && !(nor->flags &
+					  SNOR_F_NO_OP_CHIP_ERASE)) {
+			unsigned long timeout;
 
-		while (cur_cs_num < SNOR_FLASH_CNT_MAX && params) {
-			nor->spimem->spi->cs_index_mask = 0x01 << cur_cs_num;
 			ret = spi_nor_write_enable(nor);
 			if (ret)
 				goto erase_err;
@@ -1488,90 +1610,45 @@ static int spi_nor_erase(struct mtd_info *mtd, struct erase_info *instr)
 			 */
 			timeout = max(CHIP_ERASE_2MB_READY_WAIT_JIFFIES,
 				      CHIP_ERASE_2MB_READY_WAIT_JIFFIES *
-				      (unsigned long)(params->size / SZ_2M));
+				      (unsigned long)(mtd->size / SZ_2M));
 			ret = spi_nor_wait_till_ready_with_timeout(nor, timeout);
 			if (ret)
 				goto erase_err;
-			cur_cs_num++;
-		}
-
-	/* REVISIT in some cases we could speed up erasing large regions
-	 * by using SPINOR_OP_SE instead of SPINOR_OP_BE_4K.  We may have set up
-	 * to use "small sector erase", but that's not always optimal.
-	 */
 
-	/* "sector"-at-a-time erase */
-	} else if (spi_nor_has_uniform_erase(nor)) {
-		/* Determine the flash from which the operation need to start */
-		while ((cur_cs_num < SNOR_FLASH_CNT_MAX) && (addr > sz - 1) && params) {
-			cur_cs_num++;
-			params = spi_nor_get_params(nor, cur_cs_num);
-			sz += params->size;
-		}
+		/* REVISIT in some cases we could speed up erasing large regions
+		 * by using SPINOR_OP_SE instead of SPINOR_OP_BE_4K.  We may have set up
+		 * to use "small sector erase", but that's not always optimal.
+		 */
 
-		while (len) {
-			nor->spimem->spi->cs_index_mask = 0x01 << cur_cs_num;
-			ret = spi_nor_write_enable(nor);
-			if (ret)
-				goto erase_err;
+		/* "sector"-at-a-time erase */
+		} else if (spi_nor_has_uniform_erase(nor)) {
+			while (len) {
+				ret = spi_nor_write_enable(nor);
+				if (ret)
+					goto erase_err;
 
-			offset = addr;
-			if (nor->flags & SNOR_F_HAS_STACKED) {
-				params = spi_nor_get_params(nor, cur_cs_num);
-				offset -= (sz - params->size);
-			}
+				offset = addr / 2;
 
-			ret = spi_nor_erase_sector(nor, offset);
-			if (ret)
-				goto erase_err;
-
-			ret = spi_nor_wait_till_ready(nor);
-			if (ret)
-				goto erase_err;
+				ret = spi_nor_erase_sector(nor, offset);
+				if (ret)
+					goto erase_err;
 
-			addr += mtd->erasesize;
-			len -= mtd->erasesize;
+				ret = spi_nor_wait_till_ready(nor);
+				if (ret)
+					goto erase_err;
 
-			/*
-			 * Flash cross over condition in stacked mode.
-			 */
-			if ((nor->flags & SNOR_F_HAS_STACKED) && (addr > sz - 1)) {
-				cur_cs_num++;
-				params = spi_nor_get_params(nor, cur_cs_num);
-				sz += params->size;
+				addr += mtd->erasesize;
+				len -= mtd->erasesize;
 			}
-		}
-
-	/* erase multiple sectors */
-	} else {
-		u64 erase_len = 0;
 
-		/* Determine the flash from which the operation need to start */
-		while ((cur_cs_num < SNOR_FLASH_CNT_MAX) && (addr > sz - 1) && params) {
-			cur_cs_num++;
-			params = spi_nor_get_params(nor, cur_cs_num);
-			sz += params->size;
-		}
-		/* perform multi sector erase onec per Flash*/
-		while (len) {
-			erase_len = (len > (sz - addr)) ? (sz - addr) : len;
-			offset = addr;
-			nor->spimem->spi->cs_index_mask = 0x01 << cur_cs_num;
-			if (nor->flags & SNOR_F_HAS_STACKED) {
-				params = spi_nor_get_params(nor, cur_cs_num);
-				offset -= (sz - params->size);
-			}
-			ret = spi_nor_erase_multi_sectors(nor, offset, erase_len);
+		/* erase multiple sectors */
+		} else {
+			offset = addr / 2;
+			ret = spi_nor_erase_multi_sectors(nor, offset, len);
 			if (ret)
 				goto erase_err;
-			len -= erase_len;
-			addr += erase_len;
-			cur_cs_num++;
-			params = spi_nor_get_params(nor, cur_cs_num);
-			sz += params->size;
 		}
 	}
-
 	ret = spi_nor_write_disable(nor);
 
 erase_err:
@@ -1771,34 +1848,59 @@ static int spi_nor_read(struct mtd_info *mtd, loff_t from, size_t len,
 	struct spi_nor_flash_parameter *params;
 	ssize_t ret, read_len;
 	u32 cur_cs_num = 0;
-	u64 sz;
+	u_char *readbuf;
+	bool is_ofst_odd = false;
+	u64 sz = 0;
 
 	dev_dbg(nor->dev, "from 0x%08x, len %zd\n", (u32)from, len);
 
-	ret = spi_nor_lock_and_prep(nor);
-	if (ret)
-		return ret;
-
 	params = spi_nor_get_params(nor, 0);
 	sz = params->size;
 
-	/* Determine the flash from which the operation need to start */
-	while ((cur_cs_num < SNOR_FLASH_CNT_MAX) && (from > sz - 1) && params) {
-		cur_cs_num++;
-		params = spi_nor_get_params(nor, cur_cs_num);
-		sz += params->size;
+	/*
+	 * Cannot read from odd offset in parallel mode, so read
+	 * len + 1 from offset + 1 and ignore offset[0] data.
+	 */
+	if ((nor->flags & SNOR_F_HAS_PARALLEL) && (from & 0x01)) {
+		from = (loff_t)(from - 1);
+		len = (size_t)(len + 1);
+		is_ofst_odd = true;
+		readbuf = kmalloc(len, GFP_KERNEL);
+		if (!readbuf)
+			return -ENOMEM;
+	} else {
+		readbuf = buf;
+	}
+
+	if (!(nor->flags & SNOR_F_HAS_PARALLEL)) {
+		/* Determine the flash from which the operation need to start */
+		while ((cur_cs_num < SNOR_FLASH_CNT_MAX) && (from > sz - 1) && params) {
+			cur_cs_num++;
+			params = spi_nor_get_params(nor, cur_cs_num);
+			sz += params->size;
+		}
 	}
+	ret = spi_nor_lock_and_prep(nor);
+	if (ret)
+		return ret;
+
 	while (len) {
 		loff_t addr = from;
 
-		nor->spimem->spi->cs_index_mask = 0x01 << cur_cs_num;
-		read_len = (len > (sz - addr)) ? (sz - addr) : len;
-		params = spi_nor_get_params(nor, cur_cs_num);
-		addr -= (sz - params->size);
+		if (nor->flags & SNOR_F_HAS_PARALLEL) {
+			nor->spimem->spi->cs_index_mask = SPI_NOR_ENABLE_MULTI_CS;
+			read_len = len;
+			addr /= 2;
+		} else {
+			nor->spimem->spi->cs_index_mask = 1 << cur_cs_num;
+			read_len = (len > (sz - addr)) ? (sz - addr) : len;
+			params = spi_nor_get_params(nor, cur_cs_num);
+			addr -= (sz - params->size);
+		}
 
 		addr = spi_nor_convert_addr(nor, addr);
 
-		ret = spi_nor_read_data(nor, addr, len, buf);
+		ret = spi_nor_read_data(nor, addr, read_len, readbuf);
 		if (ret == 0) {
 			/* We shouldn't see 0-length reads */
 			ret = -EIO;
@@ -1808,8 +1910,20 @@ static int spi_nor_read(struct mtd_info *mtd, loff_t from, size_t len,
 			goto read_err;
 
 		WARN_ON(ret > read_len);
-		*retlen += ret;
+		if (is_ofst_odd) {
+			/*
+			 * Cannot read from odd offset in parallel mode.
+			 * So read len + 1 from offset + 1 from the flash
+			 * and copy len data from readbuf[1].
+			 */
+			memcpy(buf, (readbuf + 1), (len - 1));
+			*retlen += (ret - 1);
+		} else {
+			*retlen += ret;
+		}
 		buf += ret;
+		if (!is_ofst_odd)
+			readbuf += ret;
 		from += ret;
 		len -= ret;
 
@@ -1827,6 +1941,9 @@ static int spi_nor_read(struct mtd_info *mtd, loff_t from, size_t len,
 	ret = 0;
 
 read_err:
+	if (is_ofst_odd)
+		kfree(readbuf);
+
 	spi_nor_unlock_and_unprep(nor);
 	return ret;
 }
@@ -1852,13 +1969,38 @@ static int spi_nor_write(struct mtd_info *mtd, loff_t to, size_t len,
 	page_size = params->page_size;
 	sz = params->size;
 
-	/* Determine the flash from which the operation need to start */
-	while ((cur_cs_num < SNOR_FLASH_CNT_MAX) && (to > sz - 1) && params) {
-		cur_cs_num++;
-		params = spi_nor_get_params(nor, cur_cs_num);
-		sz += params->size;
-	}
+	if (nor->flags & SNOR_F_HAS_PARALLEL) {
+		/*
+		 * Cannot write to odd offset in parallel mode,
+		 * so write 2 byte first.
+		 */
+		if (to & 0x01) {
+			u8 two[2] = {0xff, buf[0]};
+			size_t written_len;
+
+			ret = spi_nor_write(mtd, to & ~1, 2, &written_len, two);
+			if (ret < 0)
+				return ret;
+			*retlen += 1; /* We've written only one actual byte */
+			++buf;
+			--len;
+			++to;
+		}
+		/*
+		 * Write operation are performed in page size chunks and in
+		 * parallel memories both the flashes are written simultaneously,
+		 * hence doubled the page_size.
+		 */
+		page_size <<= 1;
 
+	} else {
+		/* Determine the flash from which the operation need to start */
+		while ((cur_cs_num < SNOR_FLASH_CNT_MAX) && (to > sz - 1) && params) {
+			cur_cs_num++;
+			params = spi_nor_get_params(nor, cur_cs_num);
+			sz += params->size;
+		}
+	}
 	ret = spi_nor_lock_and_prep(nor);
 	if (ret)
 		return ret;
@@ -1882,9 +2024,14 @@ static int spi_nor_write(struct mtd_info *mtd, loff_t to, size_t len,
 		/* the size of data remaining on the first page */
 		page_remain = min_t(size_t, page_size - page_offset, len - i);
 
-		nor->spimem->spi->cs_index_mask = 0x01 << cur_cs_num;
-		params = spi_nor_get_params(nor, cur_cs_num);
-		addr -= (sz - params->size);
+		if (nor->flags & SNOR_F_HAS_PARALLEL) {
+			nor->spimem->spi->cs_index_mask = SPI_NOR_ENABLE_MULTI_CS;
+			addr /= 2;
+		} else {
+			nor->spimem->spi->cs_index_mask = 1 << cur_cs_num;
+			params = spi_nor_get_params(nor, cur_cs_num);
+			addr -= (sz - params->size);
+		}
 
 		addr = spi_nor_convert_addr(nor, addr);
 
@@ -2332,7 +2479,15 @@ static int spi_nor_select_erase(struct spi_nor *nor)
 		if (!erase)
 			return -EINVAL;
 		nor->erase_opcode = erase->opcode;
-		mtd->erasesize = erase->size;
+		/*
+		 * In parallel-memories the erase operation is
+		 * performed on both the flashes simultaneously
+		 * so, double the erasesize.
+		 */
+		if (nor->flags & SNOR_F_HAS_PARALLEL)
+			mtd->erasesize = erase->size * 2;
+		else
+			mtd->erasesize = erase->size;
 		return 0;
 	}
 
@@ -2350,7 +2505,15 @@ static int spi_nor_select_erase(struct spi_nor *nor)
 	if (!erase)
 		return -EINVAL;
 
-	mtd->erasesize = erase->size;
+	/*
+	 * In parallel-memories the erase operation is
+	 * performed on both the flashes simultaneously
+	 * so, double the erasesize.
+	 */
+	if (nor->flags & SNOR_F_HAS_PARALLEL)
+		mtd->erasesize = erase->size * 2;
+	else
+		mtd->erasesize = erase->size;
 	return 0;
 }
 
@@ -2668,7 +2831,22 @@ static void spi_nor_late_init_params(struct spi_nor *nor)
 				nor->flags |= SNOR_F_HAS_STACKED;
 		}
 	}
-	if (nor->flags & SNOR_F_HAS_STACKED) {
+	i = 0;
+	idx = 0;
+	while (i < SNOR_FLASH_CNT_MAX) {
+		rc = of_property_read_u64_index(np, "parallel-memories", idx, &flash_size[i]);
+		if (rc == -EINVAL) {
+			break;
+		} else if (rc == -EOVERFLOW) {
+			idx++;
+		} else {
+			idx++;
+			i++;
+			if (!(nor->flags & SNOR_F_HAS_PARALLEL))
+				nor->flags |= SNOR_F_HAS_PARALLEL;
+		}
+	}
+	if (nor->flags & (SNOR_F_HAS_STACKED | SNOR_F_HAS_PARALLEL)) {
 		for (idx = 1; idx < SNOR_FLASH_CNT_MAX; idx++) {
 			params = spi_nor_get_params(nor, idx);
 			params = devm_kzalloc(nor->dev, sizeof(*params), GFP_KERNEL);
@@ -2890,24 +3068,42 @@ static int spi_nor_quad_enable(struct spi_nor *nor)
 	struct spi_nor_flash_parameter *params;
 	int err, idx;
 
-	for (idx = 0; idx < SNOR_FLASH_CNT_MAX; idx++) {
-		params = spi_nor_get_params(nor, idx);
-		if (params) {
-			if (!params->quad_enable)
-				return 0;
+	if (nor->flags & SNOR_F_HAS_PARALLEL) {
+		params = spi_nor_get_params(nor, 0);
+		if (!params->quad_enable)
+			return 0;
 
-			if (!(spi_nor_get_protocol_width(nor->read_proto) == 4 ||
-			      spi_nor_get_protocol_width(nor->write_proto) == 4))
-				return 0;
-			/*
-			 * Set the appropriate CS index before
-			 * issuing the command.
-			 */
-			nor->spimem->spi->cs_index_mask = 0x01 << idx;
+		if (!(spi_nor_get_protocol_width(nor->read_proto) == 4 ||
+		      spi_nor_get_protocol_width(nor->write_proto) == 4))
+			return 0;
+		/*
+		 * In parallel mode both chip selects i.e., CS0 &
+		 * CS1 need to be asserted simulatneously.
+		 */
+		nor->spimem->spi->cs_index_mask = SPI_NOR_ENABLE_MULTI_CS;
+		err = params->quad_enable(nor);
+		if (err)
+			return err;
+	} else {
+		for (idx = 0; idx < SNOR_FLASH_CNT_MAX; idx++) {
+			params = spi_nor_get_params(nor, idx);
+			if (params) {
+				if (!params->quad_enable)
+					return 0;
 
-			err = params->quad_enable(nor);
-			if (err)
-				return err;
+				if (!(spi_nor_get_protocol_width(nor->read_proto) == 4 ||
+				      spi_nor_get_protocol_width(nor->write_proto) == 4))
+					return 0;
+				/*
+				 * Set the appropriate CS index before
+				 * issuing the command.
+				 */
+				nor->spimem->spi->cs_index_mask = 1 << idx;
+
+				err = params->quad_enable(nor);
+				if (err)
+					return err;
+			}
 		}
 	}
 	return err;
@@ -2957,17 +3153,29 @@ static int spi_nor_init(struct spi_nor *nor)
 		 */
 		WARN_ONCE(nor->flags & SNOR_F_BROKEN_RESET,
 			  "enabling reset hack; may not recover from unexpected reboots\n");
-		for (idx = 0; idx < SNOR_FLASH_CNT_MAX; idx++) {
-			params = spi_nor_get_params(nor, idx);
-			if (params) {
-				/*
-				 * Select the appropriate CS index before
-				 * issuing the command.
-				 */
-				nor->spimem->spi->cs_index_mask = 0x01 << idx;
-				err = params->set_4byte_addr_mode(nor, true);
-				if (err && err != -ENOTSUPP)
-					return err;
+		if (nor->flags & SNOR_F_HAS_PARALLEL) {
+			/*
+			 * In parallel mode both chip selects i.e., CS0 &
+			 * CS1 need to be asserted simulatneously.
+			 */
+			nor->spimem->spi->cs_index_mask = SPI_NOR_ENABLE_MULTI_CS;
+			params = spi_nor_get_params(nor, 0);
+			err = params->set_4byte_addr_mode(nor, true);
+			if (err && err != -ENOTSUPP)
+				return err;
+		} else {
+			for (idx = 0; idx < SNOR_FLASH_CNT_MAX; idx++) {
+				params = spi_nor_get_params(nor, idx);
+				if (params) {
+					/*
+					 * Select the appropriate CS index before
+					 * issuing the command.
+					 */
+					nor->spimem->spi->cs_index_mask = 1 << idx;
+					err = params->set_4byte_addr_mode(nor, true);
+					if (err && err != -ENOTSUPP)
+						return err;
+				}
 			}
 		}
 	}
@@ -3090,20 +3298,39 @@ void spi_nor_restore(struct spi_nor *nor)
 	/* restore the addressing mode */
 	if (nor->addr_nbytes == 4 && !(nor->flags & SNOR_F_4B_OPCODES) &&
 	    nor->flags & SNOR_F_BROKEN_RESET) {
-		for (idx = 0; idx < SNOR_FLASH_CNT_MAX; idx++) {
-			params = spi_nor_get_params(nor, idx);
-			if (params) {
+		if (nor->flags & SNOR_F_HAS_PARALLEL) {
+			/*
+			 * In parallel mode both chip selects i.e., CS0 &
+			 * CS1 need to be asserted simulatneously.
+			 */
+			nor->spimem->spi->cs_index_mask = SPI_NOR_ENABLE_MULTI_CS;
+			params = spi_nor_get_params(nor, 0);
+			ret = params->set_4byte_addr_mode(nor, false);
+			if (ret)
+				/*
+				 * Do not stop the execution in the hope that the flash
+				 * will default to the 3-byte address mode after the
+				 * software reset.
+				 */
+				dev_err(nor->dev,
+					"Failed to exit 4-byte address mode, err = %d\n",
+					ret);
+		} else {
+			for (idx = 0; idx < SNOR_FLASH_CNT_MAX; idx++) {
+				params = spi_nor_get_params(nor, idx);
+				if (!params)
+					break;
 				/*
 				 * Select the appropriate CS index before
 				 * issuing the command.
 				 */
-				nor->spimem->spi->cs_index_mask = 0x01 << idx;
+				nor->spimem->spi->cs_index_mask = 1 << idx;
 				ret = params->set_4byte_addr_mode(nor, false);
 				if (ret)
 					/*
-					 * Do not stop the execution in the hope that the flash
-					 * will default to the 3-byte address mode after the
-					 * software reset.
+					 * Do not stop the execution in the hope that the
+					 * flash will default to the 3-byte address mode
+					 * after the software reset.
 					 */
 					dev_err(nor->dev,
 						"Failed to exit 4-byte address mode, err = %d\n",
@@ -3193,7 +3420,16 @@ static void spi_nor_set_mtd_info(struct spi_nor *nor)
 	else
 		mtd->_erase = spi_nor_erase;
 	mtd->writesize = params->writesize;
-	mtd->writebufsize = params->page_size;
+	/*
+	 * In parallel-memories the write operation is
+	 * performed on both the flashes simultaneously
+	 * one page per flash, so double the writebufsize.
+	 */
+	if (nor->flags & SNOR_F_HAS_PARALLEL)
+		mtd->writebufsize = params->page_size << 1;
+	else
+		mtd->writebufsize = params->page_size;
+
 	for (idx = 0; idx < SNOR_FLASH_CNT_MAX; idx++) {
 		params = spi_nor_get_params(nor, idx);
 		if (params)
diff --git a/drivers/mtd/spi-nor/core.h b/drivers/mtd/spi-nor/core.h
index cff2f9c389b8..6c6df417a9c6 100644
--- a/drivers/mtd/spi-nor/core.h
+++ b/drivers/mtd/spi-nor/core.h
@@ -14,6 +14,9 @@
 /* In single configuration enable CS0 */
 #define SPI_NOR_ENABLE_CS0     BIT(0)
 
+/* In parallel configuration enable multiple CS */
+#define SPI_NOR_ENABLE_MULTI_CS	(BIT(0) | BIT(1))
+
 /* Standard SPI NOR flash operations. */
 #define SPI_NOR_READID_OP(naddr, ndummy, buf, len)			\
 	SPI_MEM_OP(SPI_MEM_OP_CMD(SPINOR_OP_RDID, 0),			\
@@ -134,6 +137,7 @@ enum spi_nor_option_flags {
 	SNOR_F_SOFT_RESET	= BIT(12),
 	SNOR_F_SWP_IS_VOLATILE	= BIT(13),
 	SNOR_F_HAS_STACKED      = BIT(14),
+	SNOR_F_HAS_PARALLEL	= BIT(15),
 };
 
 struct spi_nor_read_command {
diff --git a/drivers/mtd/spi-nor/micron-st.c b/drivers/mtd/spi-nor/micron-st.c
index b93e16094b6c..9be39f237dfc 100644
--- a/drivers/mtd/spi-nor/micron-st.c
+++ b/drivers/mtd/spi-nor/micron-st.c
@@ -357,6 +357,9 @@ static int micron_st_nor_read_fsr(struct spi_nor *nor, u8 *fsr)
 			op.data.nbytes = 2;
 		}
 
+		if (nor->flags & SNOR_F_HAS_PARALLEL)
+			op.data.nbytes = 2;
+
 		spi_nor_spimem_setup_op(nor, &op, nor->reg_proto);
 
 		ret = spi_mem_exec_op(nor->spimem, &op);
@@ -368,6 +371,8 @@ static int micron_st_nor_read_fsr(struct spi_nor *nor, u8 *fsr)
 	if (ret)
 		dev_dbg(nor->dev, "error %d reading FSR\n", ret);
 
+	if (nor->flags & SNOR_F_HAS_PARALLEL)
+		fsr[0] &= fsr[1];
 	return ret;
 }
 
-- 
2.25.1

[PATCH V6 15/15] spi: spi-zynqmp-gqspi: Add parallel memories support in GQSPI driver

[Amit Kumar Mahapatra]

During GQSPI driver probe set ctlr->multi-cs-cap for enabling multi CS
capability of the controller. In parallel mode the controller can either
split the data between both the flash or can send the same data to both the
flashes, this is determined by the STRIPE bit. While sending commands to
the flashes the GQSPI driver send the same command to both the flashes by
resetting the STRIPE bit, but while writing/reading data to & from the
flash the GQSPI driver splits the data evenly between both the flashes by
setting the STRIPE bit.

Signed-off-by: Amit Kumar Mahapatra <amit.kumar-mahapatra@amd.com>
---
 drivers/spi/spi-zynqmp-gqspi.c | 39 +++++++++++++++++++++++++++++++++-
 1 file changed, 38 insertions(+), 1 deletion(-)

diff --git a/drivers/spi/spi-zynqmp-gqspi.c b/drivers/spi/spi-zynqmp-gqspi.c
index 3d2b92a88e8a..d795d17d2541 100644
--- a/drivers/spi/spi-zynqmp-gqspi.c
+++ b/drivers/spi/spi-zynqmp-gqspi.c
@@ -23,6 +23,7 @@
 #include <linux/spinlock.h>
 #include <linux/workqueue.h>
 #include <linux/spi/spi-mem.h>
+#include <linux/mtd/spi-nor.h>
 
 /* Generic QSPI register offsets */
 #define GQSPI_CONFIG_OFST		0x00000100
@@ -192,6 +193,7 @@ struct qspi_platform_data {
  * @op_lock:		Operational lock
  * @speed_hz:          Current SPI bus clock speed in hz
  * @has_tapdelay:	Used for tapdelay register available in qspi
+ * @is_parallel:		Used for multi CS support
  */
 struct zynqmp_qspi {
 	struct spi_controller *ctlr;
@@ -214,8 +216,33 @@ struct zynqmp_qspi {
 	struct mutex op_lock;
 	u32 speed_hz;
 	bool has_tapdelay;
+	bool is_parallel;
 };
 
+/**
+ * zynqmp_gqspi_update_stripe - For GQSPI controller data stripe capabilities
+ * @op:	Pointer to mem ops
+ * Return:      Status of the data stripe
+ *
+ * Returns true if data stripe need to be enabled, else returns false
+ */
+bool zynqmp_gqspi_update_stripe(const struct spi_mem_op *op)
+{
+	if (op->cmd.opcode ==  SPINOR_OP_BE_4K ||
+	    op->cmd.opcode ==  SPINOR_OP_BE_32K ||
+	    op->cmd.opcode ==  SPINOR_OP_CHIP_ERASE ||
+	    op->cmd.opcode ==  SPINOR_OP_SE ||
+	    op->cmd.opcode ==  SPINOR_OP_BE_32K_4B ||
+	    op->cmd.opcode ==  SPINOR_OP_SE_4B ||
+	    op->cmd.opcode == SPINOR_OP_BE_4K_4B ||
+	    op->cmd.opcode ==  SPINOR_OP_WRSR ||
+	    op->cmd.opcode ==  SPINOR_OP_BRWR ||
+	    (op->cmd.opcode ==  SPINOR_OP_WRSR2 && !op->addr.nbytes))
+		return false;
+
+	return true;
+}
+
 /**
  * zynqmp_gqspi_read - For GQSPI controller read operation
  * @xqspi:	Pointer to the zynqmp_qspi structure
@@ -470,7 +497,14 @@ static void zynqmp_qspi_chipselect(struct spi_device *qspi, bool is_high)
 
 	genfifoentry |= GQSPI_GENFIFO_MODE_SPI;
 
-	if (qspi->cs_index_mask & GQSPI_SELECT_UPPER_CS) {
+	if ((qspi->cs_index_mask & GQSPI_SELECT_LOWER_CS) &&
+	    (qspi->cs_index_mask & GQSPI_SELECT_UPPER_CS)) {
+		zynqmp_gqspi_selectslave(xqspi,
+					 GQSPI_SELECT_FLASH_CS_BOTH,
+					 GQSPI_SELECT_FLASH_BUS_BOTH);
+		if (!xqspi->is_parallel)
+			xqspi->is_parallel = true;
+	} else if (qspi->cs_index_mask & GQSPI_SELECT_UPPER_CS) {
 		zynqmp_gqspi_selectslave(xqspi,
 					 GQSPI_SELECT_FLASH_CS_UPPER,
 					 GQSPI_SELECT_FLASH_BUS_LOWER);
@@ -1139,6 +1173,8 @@ static int zynqmp_qspi_exec_op(struct spi_mem *mem,
 	}
 
 	if (op->data.nbytes) {
+		if (xqspi->is_parallel && zynqmp_gqspi_update_stripe(op))
+			genfifoentry |= GQSPI_GENFIFO_STRIPE;
 		reinit_completion(&xqspi->data_completion);
 		if (op->data.dir == SPI_MEM_DATA_OUT) {
 			xqspi->txbuf = (u8 *)op->data.buf.out;
@@ -1334,6 +1370,7 @@ static int zynqmp_qspi_probe(struct platform_device *pdev)
 	ctlr->bits_per_word_mask = SPI_BPW_MASK(8);
 	ctlr->dev.of_node = np;
 	ctlr->auto_runtime_pm = true;
+	ctlr->multi_cs_cap = true;
 
 	ret = devm_spi_register_controller(&pdev->dev, ctlr);
 	if (ret) {
-- 
2.25.1

Re: (subset) [PATCH V6 00/15] Add support for stacked/parallel memories

[Mark Brown]

On Fri, 10 Mar 2023 23:02:02 +0530, Amit Kumar Mahapatra wrote:
> This patch is in the continuation to the discussions which happened on
> 'commit f89504300e94 ("spi: Stacked/parallel memories bindings")' for
> adding dt-binding support for stacked/parallel memories.
> 
> This patch series updated the spi-nor, spi core and the spi drivers
> to add stacked and parallel memories support.
> 
> [...]

Applied to

   broonie/spi.git for-next

Thanks!

[01/15] spi: Replace all spi->chip_select and spi->cs_gpiod references with function call
        commit: 9e264f3f85a56cc109cc2d6010a48aa89d5c1ff1
[02/15] net: Replace all spi->chip_select and spi->cs_gpiod references with function call
        commit: 25fd0550d9b9c92288a17fb7d605cdcdb4a65a64
[03/15] iio: imu: Replace all spi->chip_select and spi->cs_gpiod references with function call
        commit: 0183f81fce154ae1d4df2bb28d22ad6612317148
[04/15] mtd: devices: Replace all spi->chip_select and spi->cs_gpiod references with function call
        commit: 0817bcef53e4e3df23c023eddaa2b35b7288400e
[05/15] staging: Replace all spi->chip_select and spi->cs_gpiod references with function call
        commit: caa9d3475b1c5566f0272273c147cc9b72f2be28
[06/15] platform/x86: serial-multi-instantiate: Replace all spi->chip_select and spi->cs_gpiod references with function call
        commit: e20451f44ca33ec40422e9868775e117ef2da935
[07/15] powerpc/83xx/mpc832x_rdb: Replace all spi->chip_select references with function call
        commit: 3aba06a9fee04f6fefa9df71d3ee27dd4c464ad5
[08/15] ALSA: hda: cs35l41: Replace all spi->chip_select references with function call
        commit: 06b5e53c8b2b016e06a53ab6f01006ca7bbfa5df

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark

Re: [PATCH V6 09/15] spi: Add stacked and parallel memories support in SPI core

[Jonas Gorski]

Hi,

On Fri, 10 Mar 2023 at 18:37, Amit Kumar Mahapatra
<amit.kumar-mahapatra@amd.com> wrote:
>
> For supporting multiple CS the SPI device need to be aware of all the CS
> values. So, the "chip_select" member in the spi_device structure is now an
> array that holds all the CS values.
>
> spi_device structure now has a "cs_index_mask" member. This acts as an
> index to the chip_select array. If nth bit of spi->cs_index_mask is set
> then the driver would assert spi->chip_select[n].
>
> In parallel mode all the chip selects are asserted/de-asserted
> simultaneously and each byte of data is stored in both devices, the even
> bits in one, the odd bits in the other. The split is automatically handled
> by the GQSPI controller. The GQSPI controller supports a maximum of two
> flashes connected in parallel mode. A "multi-cs-cap" flag is added in the
> spi controntroller data, through ctlr->multi-cs-cap the spi core will make
> sure that the controller is capable of handling multiple chip selects at
> once.
>
> For supporting multiple CS via GPIO the cs_gpiod member of the spi_device
> structure is now an array that holds the gpio descriptor for each
> chipselect.
>
> Multi CS support using GPIO is not tested due to unavailability of
> necessary hardware setup.

Can you pinmux your SPI controller's (cs) pins as GPIO? If so, you
should be able use that for testing.

>
> Signed-off-by: Amit Kumar Mahapatra <amit.kumar-mahapatra@amd.com>
> ---
>  drivers/spi/spi.c       | 225 +++++++++++++++++++++++++++-------------
>  include/linux/spi/spi.h |  34 ++++--
>  2 files changed, 182 insertions(+), 77 deletions(-)
>
> diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
> index c725b4bab7af..742bd688381c 100644
> --- a/drivers/spi/spi.c
> +++ b/drivers/spi/spi.c
> @@ -612,10 +612,17 @@ static int spi_dev_check(struct device *dev, void *data)
>  {
>         struct spi_device *spi = to_spi_device(dev);
>         struct spi_device *new_spi = data;
> -
> -       if (spi->controller == new_spi->controller &&
> -           spi_get_chipselect(spi, 0) == spi_get_chipselect(new_spi, 0))
> -               return -EBUSY;
> +       int idx, nw_idx;
> +
> +       if (spi->controller == new_spi->controller) {
> +               for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) {
> +                       for (nw_idx = 0; nw_idx < SPI_CS_CNT_MAX; nw_idx++) {
> +                               if (spi_get_chipselect(spi, idx) ==
> +                                   spi_get_chipselect(new_spi, nw_idx))
> +                                       return -EBUSY;
> +                       }
> +               }

AFAICT unused chip selects are initialized to 0, so all single chip
select devices would have it as their second one. This will then cause
this check to reject every single chip select device after the first
one. So you first need to make sure to only compare valid chip
selects.

So the loop condition should be something along idx <
spi_get_num_chipselect(), not idx < SPI_CS_CNT_MAX.

> +       }
>         return 0;
>  }
>
> @@ -629,7 +636,7 @@ static int __spi_add_device(struct spi_device *spi)
>  {
>         struct spi_controller *ctlr = spi->controller;
>         struct device *dev = ctlr->dev.parent;
> -       int status;
> +       int status, idx;
>
>         /*
>          * We need to make sure there's no other device with this
> @@ -638,8 +645,7 @@ static int __spi_add_device(struct spi_device *spi)
>          */
>         status = bus_for_each_dev(&spi_bus_type, NULL, spi, spi_dev_check);
>         if (status) {
> -               dev_err(dev, "chipselect %d already in use\n",
> -                               spi_get_chipselect(spi, 0));
> +               dev_err(dev, "chipselect %d already in use\n", spi_get_chipselect(spi, 0));

The message might be misleading for multi cs devices where the first
one is free, but the second one is already in use.

So maybe move this error message into spi_dev_check(), where you have
that information available. You then even have the chance to state
what is using the CS then, but that might be something for a different
patch.


>                 return status;
>         }
>
> @@ -649,8 +655,10 @@ static int __spi_add_device(struct spi_device *spi)
>                 return -ENODEV;
>         }
>
> -       if (ctlr->cs_gpiods)
> -               spi_set_csgpiod(spi, 0, ctlr->cs_gpiods[spi_get_chipselect(spi, 0)]);
> +       if (ctlr->cs_gpiods) {
> +               for (idx = 0; idx < SPI_CS_CNT_MAX; idx++)
> +                       spi_set_csgpiod(spi, idx, ctlr->cs_gpiods[spi_get_chipselect(spi, idx)]);
> +       }
>
>         /*
>          * Drivers may modify this initial i/o setup, but will
> @@ -690,13 +698,15 @@ int spi_add_device(struct spi_device *spi)
>  {
>         struct spi_controller *ctlr = spi->controller;
>         struct device *dev = ctlr->dev.parent;
> -       int status;
> +       int status, idx;
>
> -       /* Chipselects are numbered 0..max; validate. */
> -       if (spi_get_chipselect(spi, 0) >= ctlr->num_chipselect) {
> -               dev_err(dev, "cs%d >= max %d\n", spi_get_chipselect(spi, 0),
> -                       ctlr->num_chipselect);
> -               return -EINVAL;
> +       for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) {
> +               /* Chipselects are numbered 0..max; validate. */
> +               if (spi_get_chipselect(spi, idx) >= ctlr->num_chipselect) {
> +                       dev_err(dev, "cs%d >= max %d\n", spi_get_chipselect(spi, idx),
> +                               ctlr->num_chipselect);
> +                       return -EINVAL;
> +               }
>         }
>
>         /* Set the bus ID string */
> @@ -713,12 +723,15 @@ static int spi_add_device_locked(struct spi_device *spi)
>  {
>         struct spi_controller *ctlr = spi->controller;
>         struct device *dev = ctlr->dev.parent;
> +       int idx;
>
> -       /* Chipselects are numbered 0..max; validate. */
> -       if (spi_get_chipselect(spi, 0) >= ctlr->num_chipselect) {
> -               dev_err(dev, "cs%d >= max %d\n", spi_get_chipselect(spi, 0),
> -                       ctlr->num_chipselect);
> -               return -EINVAL;
> +       for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) {
> +               /* Chipselects are numbered 0..max; validate. */
> +               if (spi_get_chipselect(spi, idx) >= ctlr->num_chipselect) {
> +                       dev_err(dev, "cs%d >= max %d\n", spi_get_chipselect(spi, idx),
> +                               ctlr->num_chipselect);
> +                       return -EINVAL;
> +               }
>         }
>
>         /* Set the bus ID string */
> @@ -966,58 +979,119 @@ static void spi_res_release(struct spi_controller *ctlr, struct spi_message *mes
>  static void spi_set_cs(struct spi_device *spi, bool enable, bool force)
>  {
>         bool activate = enable;
> +       u32 cs_num = __ffs(spi->cs_index_mask);
> +       int idx;
>
>         /*
> -        * Avoid calling into the driver (or doing delays) if the chip select
> -        * isn't actually changing from the last time this was called.
> +        * In parallel mode all the chip selects are asserted/de-asserted
> +        * at once
>          */
> -       if (!force && ((enable && spi->controller->last_cs == spi_get_chipselect(spi, 0)) ||
> -                      (!enable && spi->controller->last_cs != spi_get_chipselect(spi, 0))) &&
> -           (spi->controller->last_cs_mode_high == (spi->mode & SPI_CS_HIGH)))
> -               return;
> -
> -       trace_spi_set_cs(spi, activate);
> -
> -       spi->controller->last_cs = enable ? spi_get_chipselect(spi, 0) : -1;
> -       spi->controller->last_cs_mode_high = spi->mode & SPI_CS_HIGH;
> -
> -       if ((spi_get_csgpiod(spi, 0) || !spi->controller->set_cs_timing) && !activate)
> -               spi_delay_exec(&spi->cs_hold, NULL);
> -
> -       if (spi->mode & SPI_CS_HIGH)
> -               enable = !enable;
> +       if ((spi->cs_index_mask & SPI_PARALLEL_CS_MASK) == SPI_PARALLEL_CS_MASK) {
> +               spi->controller->last_cs_mode_high = spi->mode & SPI_CS_HIGH;
> +
> +               if ((spi_get_csgpiod(spi, 0) || !spi->controller->set_cs_timing) && !activate)
> +                       spi_delay_exec(&spi->cs_hold, NULL);
> +
> +               if (spi->mode & SPI_CS_HIGH)
> +                       enable = !enable;
> +
> +               if (spi_get_csgpiod(spi, 0) && spi_get_csgpiod(spi, 1)) {
> +                       if (!(spi->mode & SPI_NO_CS)) {
> +                               /*
> +                                * Historically ACPI has no means of the GPIO polarity and
> +                                * thus the SPISerialBus() resource defines it on the per-chip
> +                                * basis. In order to avoid a chain of negations, the GPIO
> +                                * polarity is considered being Active High. Even for the cases
> +                                * when _DSD() is involved (in the updated versions of ACPI)
> +                                * the GPIO CS polarity must be defined Active High to avoid
> +                                * ambiguity. That's why we use enable, that takes SPI_CS_HIGH
> +                                * into account.
> +                                */
> +                               if (has_acpi_companion(&spi->dev)) {
> +                                       for (idx = 0; idx < SPI_CS_CNT_MAX; idx++)
> +                                               gpiod_set_value_cansleep(spi_get_csgpiod(spi, idx),
> +                                                                        !enable);
> +                               } else {
> +                                       for (idx = 0; idx < SPI_CS_CNT_MAX; idx++)
> +                                               /* Polarity handled by GPIO library */
> +                                               gpiod_set_value_cansleep(spi_get_csgpiod(spi, idx),
> +                                                                        activate);
> +                               }
> +                       }
> +                       /* Some SPI masters need both GPIO CS & slave_select */
> +                       if ((spi->controller->flags & SPI_MASTER_GPIO_SS) &&
> +                           spi->controller->set_cs)
> +                               spi->controller->set_cs(spi, !enable);

> +                       else if (spi->controller->set_cs)
> +                               spi->controller->set_cs(spi, !enable);

this else if belongs to the following brace as the else of the if
(spi_get_csgpiod(spi, 0) && spi_get_csgpiod(spi, 1). Currently it
would make the first check redundant, as the second case would always
be true if the first one is.

Actually shouldn't you iterate over the cs's here in case one is using
set_cs() and the other one is gpiod? You can only get here if both are
backed by gpiods. And you would only set the first cs, but not the
second one. The ->set_cs() callback doesn't allow specifying which of
the (multiple) cs's should be set though.

> +               }
>
> -       if (spi_get_csgpiod(spi, 0)) {
> -               if (!(spi->mode & SPI_NO_CS)) {
> -                       /*
> -                        * Historically ACPI has no means of the GPIO polarity and
> -                        * thus the SPISerialBus() resource defines it on the per-chip
> -                        * basis. In order to avoid a chain of negations, the GPIO
> -                        * polarity is considered being Active High. Even for the cases
> -                        * when _DSD() is involved (in the updated versions of ACPI)
> -                        * the GPIO CS polarity must be defined Active High to avoid
> -                        * ambiguity. That's why we use enable, that takes SPI_CS_HIGH
> -                        * into account.
> -                        */
> -                       if (has_acpi_companion(&spi->dev))
> -                               gpiod_set_value_cansleep(spi_get_csgpiod(spi, 0), !enable);
> -                       else
> -                               /* Polarity handled by GPIO library */
> -                               gpiod_set_value_cansleep(spi_get_csgpiod(spi, 0), activate);
> +               for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) {
> +                       if (spi_get_csgpiod(spi, idx) || !spi->controller->set_cs_timing) {
> +                               if (activate)
> +                                       spi_delay_exec(&spi->cs_setup, NULL);
> +                               else
> +                                       spi_delay_exec(&spi->cs_inactive, NULL);
> +                       }

Won't you delay twice if both CS's are backed by gpiod (and the
controller does not implement set_cs_timing)? You should probably
break after the first or so.

I wonder if it would makes sense to have a helper function to set cs
state to all cs's indicated by cs_index_mask so you can share most of
the logic between the single and multi cs paths.

Currently it seems both paths have a lot of code (and comment)
duplication, with the difference being one path is touching one cs and
the other two (or all).

>                 }
> -               /* Some SPI masters need both GPIO CS & slave_select */
> -               if ((spi->controller->flags & SPI_MASTER_GPIO_SS) &&
> -                   spi->controller->set_cs)
> +       } else {
> +               /*
> +                * Avoid calling into the driver (or doing delays) if the chip select
> +                * isn't actually changing from the last time this was called.
> +                */
> +               if (!force && ((enable && spi->controller->last_cs ==
> +                               spi_get_chipselect(spi, cs_num)) ||
> +                               (!enable && spi->controller->last_cs !=
> +                                spi_get_chipselect(spi, cs_num))) &&
> +                   (spi->controller->last_cs_mode_high ==
> +                    (spi->mode & SPI_CS_HIGH)))
> +                       return;
> +
> +               trace_spi_set_cs(spi, activate);
> +
> +               spi->controller->last_cs = enable ? spi_get_chipselect(spi, cs_num) : -1;
> +               spi->controller->last_cs_mode_high = spi->mode & SPI_CS_HIGH;
> +
> +               if ((spi_get_csgpiod(spi, cs_num) || !spi->controller->set_cs_timing) && !activate)
> +                       spi_delay_exec(&spi->cs_hold, NULL);
> +
> +               if (spi->mode & SPI_CS_HIGH)
> +                       enable = !enable;
> +
> +               if (spi_get_csgpiod(spi, cs_num)) {
> +                       if (!(spi->mode & SPI_NO_CS)) {
> +                               /*
> +                                * Historically ACPI has no means of the GPIO polarity and
> +                                * thus the SPISerialBus() resource defines it on the per-chip
> +                                * basis. In order to avoid a chain of negations, the GPIO
> +                                * polarity is considered being Active High. Even for the cases
> +                                * when _DSD() is involved (in the updated versions of ACPI)
> +                                * the GPIO CS polarity must be defined Active High to avoid
> +                                * ambiguity. That's why we use enable, that takes SPI_CS_HIGH
> +                                * into account.
> +                                */
> +                               if (has_acpi_companion(&spi->dev))
> +                                       gpiod_set_value_cansleep(spi_get_csgpiod(spi, cs_num),
> +                                                                !enable);
> +                               else
> +                                       /* Polarity handled by GPIO library */
> +                                       gpiod_set_value_cansleep(spi_get_csgpiod(spi, cs_num),
> +                                                                activate);
> +                       }
> +                       /* Some SPI masters need both GPIO CS & slave_select */
> +                       if ((spi->controller->flags & SPI_MASTER_GPIO_SS) &&
> +                           spi->controller->set_cs)
> +                               spi->controller->set_cs(spi, !enable);
> +               } else if (spi->controller->set_cs) {
>                         spi->controller->set_cs(spi, !enable);
> -       } else if (spi->controller->set_cs) {
> -               spi->controller->set_cs(spi, !enable);
> -       }
> +               }
>
> -       if (spi_get_csgpiod(spi, 0) || !spi->controller->set_cs_timing) {
> -               if (activate)
> -                       spi_delay_exec(&spi->cs_setup, NULL);
> -               else
> -                       spi_delay_exec(&spi->cs_inactive, NULL);
> +               if (spi_get_csgpiod(spi, cs_num) || !spi->controller->set_cs_timing) {
> +                       if (activate)
> +                               spi_delay_exec(&spi->cs_setup, NULL);
> +                       else
> +                               spi_delay_exec(&spi->cs_inactive, NULL);
> +               }
>         }
>  }
>
> @@ -2246,8 +2320,8 @@ static void of_spi_parse_dt_cs_delay(struct device_node *nc,
>  static int of_spi_parse_dt(struct spi_controller *ctlr, struct spi_device *spi,
>                            struct device_node *nc)
>  {
> -       u32 value;
> -       int rc;
> +       u32 value, cs[SPI_CS_CNT_MAX] = {0};
> +       int rc, idx;
>
>         /* Mode (clock phase/polarity/etc.) */
>         if (of_property_read_bool(nc, "spi-cpha"))
> @@ -2320,13 +2394,21 @@ static int of_spi_parse_dt(struct spi_controller *ctlr, struct spi_device *spi,
>         }
>
>         /* Device address */
> -       rc = of_property_read_u32(nc, "reg", &value);
> -       if (rc) {
> +       rc = of_property_read_variable_u32_array(nc, "reg", &cs[0], 1,
> +                                                SPI_CS_CNT_MAX);
> +       if (rc < 0 || rc > ctlr->num_chipselect) {
>                 dev_err(&ctlr->dev, "%pOF has no valid 'reg' property (%d)\n",
>                         nc, rc);
>                 return rc;
> +       } else if ((of_property_read_bool(nc, "parallel-memories")) &&
> +                  (!ctlr->multi_cs_cap)) {
> +               dev_err(&ctlr->dev, "SPI controller doesn't support multi CS\n");
> +               return -EINVAL;
>         }
> -       spi_set_chipselect(spi, 0, value);
> +       for (idx = 0; idx < rc; idx++)
> +               spi_set_chipselect(spi, idx, cs[idx]);
> +       /* By default set the spi->cs_index_mask as 1 */
> +       spi->cs_index_mask = 0x01;
>
>         /* Device speed */
>         if (!of_property_read_u32(nc, "spi-max-frequency", &value))
> @@ -3846,6 +3928,7 @@ static int __spi_validate(struct spi_device *spi, struct spi_message *message)
>         struct spi_controller *ctlr = spi->controller;
>         struct spi_transfer *xfer;
>         int w_size;
> +       u32 cs_num = __ffs(spi->cs_index_mask);
>
>         if (list_empty(&message->transfers))
>                 return -EINVAL;
> @@ -3858,7 +3941,7 @@ static int __spi_validate(struct spi_device *spi, struct spi_message *message)
>          * cs_change is set for each transfer.
>          */
>         if ((spi->mode & SPI_CS_WORD) && (!(ctlr->mode_bits & SPI_CS_WORD) ||
> -                                         spi_get_csgpiod(spi, 0))) {
> +                                         spi_get_csgpiod(spi, cs_num))) {

Wouldn't you need to check for any of the cs_index_mask enabled CS's,
and not just the first one? AFAICT you would currently fail to catch a
SPI_CS_WORD transfer with both cs enabled where the first one is a
SPI_CS_WORD capable native CS and the second one a gpiod.

>                 size_t maxsize;
>                 int ret;
>
> diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
> index bdb35a91b4bf..452682aa1a39 100644
> --- a/include/linux/spi/spi.h
> +++ b/include/linux/spi/spi.h
> @@ -19,6 +19,11 @@
>  #include <linux/acpi.h>
>  #include <linux/u64_stats_sync.h>
>
> +/* Max no. of CS supported per spi device */
> +#define SPI_CS_CNT_MAX 2
> +
> +/* chip select mask */
> +#define SPI_PARALLEL_CS_MASK   (BIT(0) | BIT(1))
>  struct dma_chan;
>  struct software_node;
>  struct ptp_system_timestamp;
> @@ -166,6 +171,7 @@ extern void spi_transfer_cs_change_delay_exec(struct spi_message *msg,
>   *     deasserted. If @cs_change_delay is used from @spi_transfer, then the
>   *     two delays will be added up.
>   * @pcpu_statistics: statistics for the spi_device
> + * @cs_index_mask: Bit mask of the active chipselect(s) in the chipselect array
>   *
>   * A @spi_device is used to interchange data between an SPI slave
>   * (usually a discrete chip) and CPU memory.
> @@ -181,7 +187,7 @@ struct spi_device {
>         struct spi_controller   *controller;
>         struct spi_controller   *master;        /* Compatibility layer */
>         u32                     max_speed_hz;
> -       u8                      chip_select;
> +       u8                      chip_select[SPI_CS_CNT_MAX];
>         u8                      bits_per_word;
>         bool                    rt;
>  #define SPI_NO_TX      BIT(31)         /* No transmit wire */
> @@ -202,7 +208,7 @@ struct spi_device {
>         void                    *controller_data;
>         char                    modalias[SPI_NAME_SIZE];
>         const char              *driver_override;
> -       struct gpio_desc        *cs_gpiod;      /* Chip select gpio desc */
> +       struct gpio_desc        *cs_gpiod[SPI_CS_CNT_MAX];      /* Chip select gpio desc */
>         struct spi_delay        word_delay; /* Inter-word delay */
>         /* CS delays */
>         struct spi_delay        cs_setup;
> @@ -212,6 +218,13 @@ struct spi_device {
>         /* The statistics */
>         struct spi_statistics __percpu  *pcpu_statistics;
>
> +       /* Bit mask of the chipselect(s) that the driver need to use from
> +        * the chipselect array.When the controller is capable to handle
> +        * multiple chip selects & memories are connected in parallel
> +        * then more than one bit need to be set in cs_index_mask.
> +        */
> +       u32                     cs_index_mask : 2;

SPI_CS_CNT_MAX?

> +
>         /*
>          * likely need more hooks for more protocol options affecting how
>          * the controller talks to each chip, like:
> @@ -268,22 +281,22 @@ static inline void *spi_get_drvdata(struct spi_device *spi)
>
>  static inline u8 spi_get_chipselect(struct spi_device *spi, u8 idx)
>  {
> -       return spi->chip_select;
> +       return spi->chip_select[idx];
>  }
>
>  static inline void spi_set_chipselect(struct spi_device *spi, u8 idx, u8 chipselect)
>  {
> -       spi->chip_select = chipselect;
> +       spi->chip_select[idx] = chipselect;
>  }
>
>  static inline struct gpio_desc *spi_get_csgpiod(struct spi_device *spi, u8 idx)
>  {
> -       return spi->cs_gpiod;
> +       return spi->cs_gpiod[idx];
>  }
>
>  static inline void spi_set_csgpiod(struct spi_device *spi, u8 idx, struct gpio_desc *csgpiod)
>  {
> -       spi->cs_gpiod = csgpiod;
> +       spi->cs_gpiod[idx] = csgpiod;
>  }
>
>  /**
> @@ -388,6 +401,8 @@ extern struct spi_device *spi_new_ancillary_device(struct spi_device *spi, u8 ch
>   * @bus_lock_spinlock: spinlock for SPI bus locking
>   * @bus_lock_mutex: mutex for exclusion of multiple callers
>   * @bus_lock_flag: indicates that the SPI bus is locked for exclusive use
> + * @multi_cs_cap: indicates that the SPI Controller can assert/de-assert
> + *     more than one chip select at once.
>   * @setup: updates the device mode and clocking records used by a
>   *     device's SPI controller; protocol code may call this.  This
>   *     must fail if an unrecognized or unsupported mode is requested.
> @@ -585,6 +600,13 @@ struct spi_controller {
>         /* Flag indicating that the SPI bus is locked for exclusive use */
>         bool                    bus_lock_flag;
>
> +       /*
> +        * Flag indicating that the spi-controller has multi chip select
> +        * capability and can assert/de-assert more than one chip select
> +        * at once.
> +        */
> +       bool                    multi_cs_cap;

I admit I haven't followed the first iterations, but Is there a reason
this isn't a SPI_XXX flag in spi.h? There seem to be quite a few free
bits left.

I would think multi_cs can be emulated (somewhat) via gpiod for the
second CS as long as the controller supports set_cs() (and
SPI_NO_CS?).

> +
>         /* Setup mode and clock, etc (spi driver may call many times).
>          *
>          * IMPORTANT:  this may be called when transfers to another
> --
> 2.25.1
>

Regards
Jonas

RE: [PATCH V6 09/15] spi: Add stacked and parallel memories support in SPI core

[Stefan Binding]

Hi,

I tested this patch on an existing laptop which uses SPI with a GPIO
Chipselect,
(HP EliteBook 860 G9), and I get the error:

[    2.671655] pxa2xx-spi pxa2xx-spi.2: chipselect 1 already in use
[    2.671711] spi_master spi0: error -EBUSY: failed to add SPI device
CSC3551:00 from ACPI
[    2.690903] Serial bus multi instantiate pseudo device driver:
probe of CSC3551:00 failed with error -16

Please don't merge this until we have fully investigated.

Thanks,
Stefan Binding

> -----Original Message-----
> From: Amit Kumar Mahapatra <amit.kumar-mahapatra@amd.com>
> Sent: 10 March 2023 17:32
> To: broonie@kernel.org; miquel.raynal@bootlin.com; richard@nod.at;
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> amitrkcian2002@gmail.com; amit.kumar-mahapatra@amd.com
> Subject: [PATCH V6 09/15] spi: Add stacked and parallel memories
> support in SPI core
> 
> For supporting multiple CS the SPI device need to be aware of all
the
> CS
> values. So, the "chip_select" member in the spi_device structure is
> now an
> array that holds all the CS values.
> 
> spi_device structure now has a "cs_index_mask" member. This acts as
> an
> index to the chip_select array. If nth bit of spi->cs_index_mask is
set
> then the driver would assert spi->chip_select[n].
> 
> In parallel mode all the chip selects are asserted/de-asserted
> simultaneously and each byte of data is stored in both devices, the
> even
> bits in one, the odd bits in the other. The split is automatically
handled
> by the GQSPI controller. The GQSPI controller supports a maximum of
> two
> flashes connected in parallel mode. A "multi-cs-cap" flag is added
in
> the
> spi controntroller data, through ctlr->multi-cs-cap the spi core
will
> make
> sure that the controller is capable of handling multiple chip
selects at
> once.
> 
> For supporting multiple CS via GPIO the cs_gpiod member of the
> spi_device
> structure is now an array that holds the gpio descriptor for each
> chipselect.
> 
> Multi CS support using GPIO is not tested due to unavailability of
> necessary hardware setup.
> 
> Signed-off-by: Amit Kumar Mahapatra <amit.kumar-
> mahapatra@amd.com>
> ---
>  drivers/spi/spi.c       | 225
+++++++++++++++++++++++++++------------
> -
>  include/linux/spi/spi.h |  34 ++++--
>  2 files changed, 182 insertions(+), 77 deletions(-)
> 
> diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
> index c725b4bab7af..742bd688381c 100644
> --- a/drivers/spi/spi.c
> +++ b/drivers/spi/spi.c
> @@ -612,10 +612,17 @@ static int spi_dev_check(struct device *dev,
> void *data)
>  {
>  	struct spi_device *spi = to_spi_device(dev);
>  	struct spi_device *new_spi = data;
> -
> -	if (spi->controller == new_spi->controller &&
> -	    spi_get_chipselect(spi, 0) == spi_get_chipselect(new_spi,
0))
> -		return -EBUSY;
> +	int idx, nw_idx;
> +
> +	if (spi->controller == new_spi->controller) {
> +		for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) {
> +			for (nw_idx = 0; nw_idx < SPI_CS_CNT_MAX;
> nw_idx++) {
> +				if (spi_get_chipselect(spi, idx) ==
> +				    spi_get_chipselect(new_spi,
> nw_idx))
> +					return -EBUSY;
> +			}
> +		}
> +	}
>  	return 0;
>  }
> 
> @@ -629,7 +636,7 @@ static int __spi_add_device(struct spi_device
> *spi)
>  {
>  	struct spi_controller *ctlr = spi->controller;
>  	struct device *dev = ctlr->dev.parent;
> -	int status;
> +	int status, idx;
> 
>  	/*
>  	 * We need to make sure there's no other device with this
> @@ -638,8 +645,7 @@ static int __spi_add_device(struct spi_device
> *spi)
>  	 */
>  	status = bus_for_each_dev(&spi_bus_type, NULL, spi,
> spi_dev_check);
>  	if (status) {
> -		dev_err(dev, "chipselect %d already in use\n",
> -				spi_get_chipselect(spi, 0));
> +		dev_err(dev, "chipselect %d already in use\n",
> spi_get_chipselect(spi, 0));
>  		return status;
>  	}
> 
> @@ -649,8 +655,10 @@ static int __spi_add_device(struct spi_device
> *spi)
>  		return -ENODEV;
>  	}
> 
> -	if (ctlr->cs_gpiods)
> -		spi_set_csgpiod(spi, 0, ctlr-
> >cs_gpiods[spi_get_chipselect(spi, 0)]);
> +	if (ctlr->cs_gpiods) {
> +		for (idx = 0; idx < SPI_CS_CNT_MAX; idx++)
> +			spi_set_csgpiod(spi, idx, ctlr-
> >cs_gpiods[spi_get_chipselect(spi, idx)]);
> +	}
> 
>  	/*
>  	 * Drivers may modify this initial i/o setup, but will
> @@ -690,13 +698,15 @@ int spi_add_device(struct spi_device *spi)
>  {
>  	struct spi_controller *ctlr = spi->controller;
>  	struct device *dev = ctlr->dev.parent;
> -	int status;
> +	int status, idx;
> 
> -	/* Chipselects are numbered 0..max; validate. */
> -	if (spi_get_chipselect(spi, 0) >= ctlr->num_chipselect) {
> -		dev_err(dev, "cs%d >= max %d\n",
> spi_get_chipselect(spi, 0),
> -			ctlr->num_chipselect);
> -		return -EINVAL;
> +	for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) {
> +		/* Chipselects are numbered 0..max; validate. */
> +		if (spi_get_chipselect(spi, idx) >= ctlr-
> >num_chipselect) {
> +			dev_err(dev, "cs%d >= max %d\n",
> spi_get_chipselect(spi, idx),
> +				ctlr->num_chipselect);
> +			return -EINVAL;
> +		}
>  	}
> 
>  	/* Set the bus ID string */
> @@ -713,12 +723,15 @@ static int spi_add_device_locked(struct
> spi_device *spi)
>  {
>  	struct spi_controller *ctlr = spi->controller;
>  	struct device *dev = ctlr->dev.parent;
> +	int idx;
> 
> -	/* Chipselects are numbered 0..max; validate. */
> -	if (spi_get_chipselect(spi, 0) >= ctlr->num_chipselect) {
> -		dev_err(dev, "cs%d >= max %d\n",
> spi_get_chipselect(spi, 0),
> -			ctlr->num_chipselect);
> -		return -EINVAL;
> +	for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) {
> +		/* Chipselects are numbered 0..max; validate. */
> +		if (spi_get_chipselect(spi, idx) >= ctlr-
> >num_chipselect) {
> +			dev_err(dev, "cs%d >= max %d\n",
> spi_get_chipselect(spi, idx),
> +				ctlr->num_chipselect);
> +			return -EINVAL;
> +		}
>  	}
> 
>  	/* Set the bus ID string */
> @@ -966,58 +979,119 @@ static void spi_res_release(struct
> spi_controller *ctlr, struct spi_message *mes
>  static void spi_set_cs(struct spi_device *spi, bool enable, bool
force)
>  {
>  	bool activate = enable;
> +	u32 cs_num = __ffs(spi->cs_index_mask);
> +	int idx;
> 
>  	/*
> -	 * Avoid calling into the driver (or doing delays) if the chip
> select
> -	 * isn't actually changing from the last time this was called.
> +	 * In parallel mode all the chip selects are
asserted/de-asserted
> +	 * at once
>  	 */
> -	if (!force && ((enable && spi->controller->last_cs ==
> spi_get_chipselect(spi, 0)) ||
> -		       (!enable && spi->controller->last_cs !=
> spi_get_chipselect(spi, 0))) &&
> -	    (spi->controller->last_cs_mode_high == (spi->mode &
> SPI_CS_HIGH)))
> -		return;
> -
> -	trace_spi_set_cs(spi, activate);
> -
> -	spi->controller->last_cs = enable ? spi_get_chipselect(spi, 0)
: -
> 1;
> -	spi->controller->last_cs_mode_high = spi->mode &
> SPI_CS_HIGH;
> -
> -	if ((spi_get_csgpiod(spi, 0) ||
!spi->controller->set_cs_timing)
> && !activate)
> -		spi_delay_exec(&spi->cs_hold, NULL);
> -
> -	if (spi->mode & SPI_CS_HIGH)
> -		enable = !enable;
> +	if ((spi->cs_index_mask & SPI_PARALLEL_CS_MASK) ==
> SPI_PARALLEL_CS_MASK) {
> +		spi->controller->last_cs_mode_high = spi->mode &
> SPI_CS_HIGH;
> +
> +		if ((spi_get_csgpiod(spi, 0) || !spi->controller-
> >set_cs_timing) && !activate)
> +			spi_delay_exec(&spi->cs_hold, NULL);
> +
> +		if (spi->mode & SPI_CS_HIGH)
> +			enable = !enable;
> +
> +		if (spi_get_csgpiod(spi, 0) && spi_get_csgpiod(spi,
1)) {
> +			if (!(spi->mode & SPI_NO_CS)) {
> +				/*
> +				 * Historically ACPI has no means of
the
> GPIO polarity and
> +				 * thus the SPISerialBus() resource
> defines it on the per-chip
> +				 * basis. In order to avoid a chain of
> negations, the GPIO
> +				 * polarity is considered being Active
> High. Even for the cases
> +				 * when _DSD() is involved (in the
> updated versions of ACPI)
> +				 * the GPIO CS polarity must be
> defined Active High to avoid
> +				 * ambiguity. That's why we use
> enable, that takes SPI_CS_HIGH
> +				 * into account.
> +				 */
> +				if (has_acpi_companion(&spi->dev)) {
> +					for (idx = 0; idx <
> SPI_CS_CNT_MAX; idx++)
> +
> 	gpiod_set_value_cansleep(spi_get_csgpiod(spi, idx),
> +
> !enable);
> +				} else {
> +					for (idx = 0; idx <
> SPI_CS_CNT_MAX; idx++)
> +						/* Polarity handled by
> GPIO library */
> +
> 	gpiod_set_value_cansleep(spi_get_csgpiod(spi, idx),
> +
> activate);
> +				}
> +			}
> +			/* Some SPI masters need both GPIO CS &
> slave_select */
> +			if ((spi->controller->flags &
> SPI_MASTER_GPIO_SS) &&
> +			    spi->controller->set_cs)
> +				spi->controller->set_cs(spi, !enable);
> +			else if (spi->controller->set_cs)
> +				spi->controller->set_cs(spi, !enable);
> +		}
> 
> -	if (spi_get_csgpiod(spi, 0)) {
> -		if (!(spi->mode & SPI_NO_CS)) {
> -			/*
> -			 * Historically ACPI has no means of the GPIO
> polarity and
> -			 * thus the SPISerialBus() resource defines it
on
> the per-chip
> -			 * basis. In order to avoid a chain of
negations,
> the GPIO
> -			 * polarity is considered being Active High.
Even
> for the cases
> -			 * when _DSD() is involved (in the updated
> versions of ACPI)
> -			 * the GPIO CS polarity must be defined Active
> High to avoid
> -			 * ambiguity. That's why we use enable, that
> takes SPI_CS_HIGH
> -			 * into account.
> -			 */
> -			if (has_acpi_companion(&spi->dev))
> -
> 	gpiod_set_value_cansleep(spi_get_csgpiod(spi, 0), !enable);
> -			else
> -				/* Polarity handled by GPIO library */
> -
> 	gpiod_set_value_cansleep(spi_get_csgpiod(spi, 0), activate);
> +		for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) {
> +			if (spi_get_csgpiod(spi, idx) ||
!spi->controller-
> >set_cs_timing) {
> +				if (activate)
> +					spi_delay_exec(&spi-
> >cs_setup, NULL);
> +				else
> +					spi_delay_exec(&spi-
> >cs_inactive, NULL);
> +			}
>  		}
> -		/* Some SPI masters need both GPIO CS &
> slave_select */
> -		if ((spi->controller->flags & SPI_MASTER_GPIO_SS) &&
> -		    spi->controller->set_cs)
> +	} else {
> +		/*
> +		 * Avoid calling into the driver (or doing delays) if
the
> chip select
> +		 * isn't actually changing from the last time this was
> called.
> +		 */
> +		if (!force && ((enable && spi->controller->last_cs ==
> +				spi_get_chipselect(spi, cs_num)) ||
> +				(!enable && spi->controller->last_cs
!=
> +				 spi_get_chipselect(spi, cs_num))) &&
> +		    (spi->controller->last_cs_mode_high ==
> +		     (spi->mode & SPI_CS_HIGH)))
> +			return;
> +
> +		trace_spi_set_cs(spi, activate);
> +
> +		spi->controller->last_cs = enable ?
> spi_get_chipselect(spi, cs_num) : -1;
> +		spi->controller->last_cs_mode_high = spi->mode &
> SPI_CS_HIGH;
> +
> +		if ((spi_get_csgpiod(spi, cs_num) || !spi->controller-
> >set_cs_timing) && !activate)
> +			spi_delay_exec(&spi->cs_hold, NULL);
> +
> +		if (spi->mode & SPI_CS_HIGH)
> +			enable = !enable;
> +
> +		if (spi_get_csgpiod(spi, cs_num)) {
> +			if (!(spi->mode & SPI_NO_CS)) {
> +				/*
> +				 * Historically ACPI has no means of
the
> GPIO polarity and
> +				 * thus the SPISerialBus() resource
> defines it on the per-chip
> +				 * basis. In order to avoid a chain of
> negations, the GPIO
> +				 * polarity is considered being Active
> High. Even for the cases
> +				 * when _DSD() is involved (in the
> updated versions of ACPI)
> +				 * the GPIO CS polarity must be
> defined Active High to avoid
> +				 * ambiguity. That's why we use
> enable, that takes SPI_CS_HIGH
> +				 * into account.
> +				 */
> +				if (has_acpi_companion(&spi->dev))
> +
> 	gpiod_set_value_cansleep(spi_get_csgpiod(spi, cs_num),
> +
> !enable);
> +				else
> +					/* Polarity handled by GPIO
> library */
> +
> 	gpiod_set_value_cansleep(spi_get_csgpiod(spi, cs_num),
> +
> activate);
> +			}
> +			/* Some SPI masters need both GPIO CS &
> slave_select */
> +			if ((spi->controller->flags &
> SPI_MASTER_GPIO_SS) &&
> +			    spi->controller->set_cs)
> +				spi->controller->set_cs(spi, !enable);
> +		} else if (spi->controller->set_cs) {
>  			spi->controller->set_cs(spi, !enable);
> -	} else if (spi->controller->set_cs) {
> -		spi->controller->set_cs(spi, !enable);
> -	}
> +		}
> 
> -	if (spi_get_csgpiod(spi, 0) ||
!spi->controller->set_cs_timing) {
> -		if (activate)
> -			spi_delay_exec(&spi->cs_setup, NULL);
> -		else
> -			spi_delay_exec(&spi->cs_inactive, NULL);
> +		if (spi_get_csgpiod(spi, cs_num) || !spi->controller-
> >set_cs_timing) {
> +			if (activate)
> +				spi_delay_exec(&spi->cs_setup,
> NULL);
> +			else
> +				spi_delay_exec(&spi->cs_inactive,
> NULL);
> +		}
>  	}
>  }
> 
> @@ -2246,8 +2320,8 @@ static void of_spi_parse_dt_cs_delay(struct
> device_node *nc,
>  static int of_spi_parse_dt(struct spi_controller *ctlr, struct
spi_device
> *spi,
>  			   struct device_node *nc)
>  {
> -	u32 value;
> -	int rc;
> +	u32 value, cs[SPI_CS_CNT_MAX] = {0};
> +	int rc, idx;
> 
>  	/* Mode (clock phase/polarity/etc.) */
>  	if (of_property_read_bool(nc, "spi-cpha"))
> @@ -2320,13 +2394,21 @@ static int of_spi_parse_dt(struct
> spi_controller *ctlr, struct spi_device *spi,
>  	}
> 
>  	/* Device address */
> -	rc = of_property_read_u32(nc, "reg", &value);
> -	if (rc) {
> +	rc = of_property_read_variable_u32_array(nc, "reg", &cs[0], 1,
> +						 SPI_CS_CNT_MAX);
> +	if (rc < 0 || rc > ctlr->num_chipselect) {
>  		dev_err(&ctlr->dev, "%pOF has no valid 'reg' property
> (%d)\n",
>  			nc, rc);
>  		return rc;
> +	} else if ((of_property_read_bool(nc, "parallel-memories"))
> &&
> +		   (!ctlr->multi_cs_cap)) {
> +		dev_err(&ctlr->dev, "SPI controller doesn't support
> multi CS\n");
> +		return -EINVAL;
>  	}
> -	spi_set_chipselect(spi, 0, value);
> +	for (idx = 0; idx < rc; idx++)
> +		spi_set_chipselect(spi, idx, cs[idx]);
> +	/* By default set the spi->cs_index_mask as 1 */
> +	spi->cs_index_mask = 0x01;
> 
>  	/* Device speed */
>  	if (!of_property_read_u32(nc, "spi-max-frequency", &value))
> @@ -3846,6 +3928,7 @@ static int __spi_validate(struct spi_device
> *spi, struct spi_message *message)
>  	struct spi_controller *ctlr = spi->controller;
>  	struct spi_transfer *xfer;
>  	int w_size;
> +	u32 cs_num = __ffs(spi->cs_index_mask);
> 
>  	if (list_empty(&message->transfers))
>  		return -EINVAL;
> @@ -3858,7 +3941,7 @@ static int __spi_validate(struct spi_device
> *spi, struct spi_message *message)
>  	 * cs_change is set for each transfer.
>  	 */
>  	if ((spi->mode & SPI_CS_WORD) && (!(ctlr->mode_bits &
> SPI_CS_WORD) ||
> -					  spi_get_csgpiod(spi, 0))) {
> +					  spi_get_csgpiod(spi,
> cs_num))) {
>  		size_t maxsize;
>  		int ret;
> 
> diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
> index bdb35a91b4bf..452682aa1a39 100644
> --- a/include/linux/spi/spi.h
> +++ b/include/linux/spi/spi.h
> @@ -19,6 +19,11 @@
>  #include <linux/acpi.h>
>  #include <linux/u64_stats_sync.h>
> 
> +/* Max no. of CS supported per spi device */
> +#define SPI_CS_CNT_MAX 2
> +
> +/* chip select mask */
> +#define SPI_PARALLEL_CS_MASK	(BIT(0) | BIT(1))
>  struct dma_chan;
>  struct software_node;
>  struct ptp_system_timestamp;
> @@ -166,6 +171,7 @@ extern void
> spi_transfer_cs_change_delay_exec(struct spi_message *msg,
>   *	deasserted. If @cs_change_delay is used from @spi_transfer,
> then the
>   *	two delays will be added up.
>   * @pcpu_statistics: statistics for the spi_device
> + * @cs_index_mask: Bit mask of the active chipselect(s) in the
> chipselect array
>   *
>   * A @spi_device is used to interchange data between an SPI slave
>   * (usually a discrete chip) and CPU memory.
> @@ -181,7 +187,7 @@ struct spi_device {
>  	struct spi_controller	*controller;
>  	struct spi_controller	*master;	/* Compatibility layer
> */
>  	u32			max_speed_hz;
> -	u8			chip_select;
> +	u8			chip_select[SPI_CS_CNT_MAX];
>  	u8			bits_per_word;
>  	bool			rt;
>  #define SPI_NO_TX	BIT(31)		/* No transmit wire */
> @@ -202,7 +208,7 @@ struct spi_device {
>  	void			*controller_data;
>  	char			modalias[SPI_NAME_SIZE];
>  	const char		*driver_override;
> -	struct gpio_desc	*cs_gpiod;	/* Chip select gpio
desc
> */
> +	struct gpio_desc	*cs_gpiod[SPI_CS_CNT_MAX];	/*
Chip
> select gpio desc */
>  	struct spi_delay	word_delay; /* Inter-word delay */
>  	/* CS delays */
>  	struct spi_delay	cs_setup;
> @@ -212,6 +218,13 @@ struct spi_device {
>  	/* The statistics */
>  	struct spi_statistics __percpu	*pcpu_statistics;
> 
> +	/* Bit mask of the chipselect(s) that the driver need to use
> from
> +	 * the chipselect array.When the controller is capable to
handle
> +	 * multiple chip selects & memories are connected in parallel
> +	 * then more than one bit need to be set in cs_index_mask.
> +	 */
> +	u32			cs_index_mask : 2;
> +
>  	/*
>  	 * likely need more hooks for more protocol options affecting
> how
>  	 * the controller talks to each chip, like:
> @@ -268,22 +281,22 @@ static inline void *spi_get_drvdata(struct
> spi_device *spi)
> 
>  static inline u8 spi_get_chipselect(struct spi_device *spi, u8 idx)
>  {
> -	return spi->chip_select;
> +	return spi->chip_select[idx];
>  }
> 
>  static inline void spi_set_chipselect(struct spi_device *spi, u8
idx, u8
> chipselect)
>  {
> -	spi->chip_select = chipselect;
> +	spi->chip_select[idx] = chipselect;
>  }
> 
>  static inline struct gpio_desc *spi_get_csgpiod(struct spi_device
*spi,
> u8 idx)
>  {
> -	return spi->cs_gpiod;
> +	return spi->cs_gpiod[idx];
>  }
> 
>  static inline void spi_set_csgpiod(struct spi_device *spi, u8 idx,
struct
> gpio_desc *csgpiod)
>  {
> -	spi->cs_gpiod = csgpiod;
> +	spi->cs_gpiod[idx] = csgpiod;
>  }
> 
>  /**
> @@ -388,6 +401,8 @@ extern struct spi_device
> *spi_new_ancillary_device(struct spi_device *spi, u8 ch
>   * @bus_lock_spinlock: spinlock for SPI bus locking
>   * @bus_lock_mutex: mutex for exclusion of multiple callers
>   * @bus_lock_flag: indicates that the SPI bus is locked for
exclusive
> use
> + * @multi_cs_cap: indicates that the SPI Controller can assert/de-
> assert
> + *	more than one chip select at once.
>   * @setup: updates the device mode and clocking records used by a
>   *	device's SPI controller; protocol code may call this.  This
>   *	must fail if an unrecognized or unsupported mode is
> requested.
> @@ -585,6 +600,13 @@ struct spi_controller {
>  	/* Flag indicating that the SPI bus is locked for exclusive
use */
>  	bool			bus_lock_flag;
> 
> +	/*
> +	 * Flag indicating that the spi-controller has multi chip
select
> +	 * capability and can assert/de-assert more than one chip
> select
> +	 * at once.
> +	 */
> +	bool			multi_cs_cap;
> +
>  	/* Setup mode and clock, etc (spi driver may call many times).
>  	 *
>  	 * IMPORTANT:  this may be called when transfers to another
> --
> 2.25.1

RE: [PATCH V6 09/15] spi: Add stacked and parallel memories support in SPI core

[Mahapatra, Amit Kumar]

Hello,

> -----Original Message-----
> From: Jonas Gorski <jonas.gorski@gmail.com>
> Sent: Sunday, March 12, 2023 9:30 PM
> To: Mahapatra, Amit Kumar <amit.kumar-mahapatra@amd.com>
> Cc: broonie@kernel.org; miquel.raynal@bootlin.com; richard@nod.at;
> vigneshr@ti.com; jic23@kernel.org; tudor.ambarus@microchip.com;
> pratyush@kernel.org; Mehta, Sanju <Sanju.Mehta@amd.com>; chin-
> ting_kuo@aspeedtech.com; clg@kaod.org; kdasu.kdev@gmail.com;
> f.fainelli@gmail.com; rjui@broadcom.com; sbranden@broadcom.com;
> eajames@linux.ibm.com; olteanv@gmail.com; han.xu@nxp.com;
> john.garry@huawei.com; shawnguo@kernel.org; s.hauer@pengutronix.de;
> narmstrong@baylibre.com; khilman@baylibre.com;
> matthias.bgg@gmail.com; haibo.chen@nxp.com; linus.walleij@linaro.org;
> daniel@zonque.org; haojian.zhuang@gmail.com; robert.jarzmik@free.fr;
> agross@kernel.org; bjorn.andersson@linaro.org; heiko@sntech.de;
> krzysztof.kozlowski@linaro.org; andi@etezian.org;
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> william.zhang@broadcom.com; kursad.oney@broadcom.com;
> anand.gore@broadcom.com; rafal@milecki.pl; git (AMD-Xilinx)
> <git@amd.com>; linux-spi@vger.kernel.org; linux-kernel@vger.kernel.org;
> joel@jms.id.au; andrew@aj.id.au; radu_nicolae.pirea@upb.ro;
> nicolas.ferre@microchip.com; alexandre.belloni@bootlin.com;
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> Simek, Michal <michal.simek@amd.com>; linux-aspeed@lists.ozlabs.org;
> openbmc@lists.ozlabs.org; linux-arm-kernel@lists.infradead.org; linux-rpi-
> kernel@lists.infradead.org; linux-amlogic@lists.infradead.org; linux-
> mediatek@lists.infradead.org; linux-arm-msm@vger.kernel.org; linux-
> rockchip@lists.infradead.org; linux-samsung-soc@vger.kernel.org; linux-
> stm32@st-md-mailman.stormreply.com; linux-sunxi@lists.linux.dev; linux-
> tegra@vger.kernel.org; netdev@vger.kernel.org; linux-
> wpan@vger.kernel.org; libertas-dev@lists.infradead.org; linux-
> wireless@vger.kernel.org; linux-mtd@lists.infradead.org; lars@metafoo.de;
> Michael.Hennerich@analog.com; linux-iio@vger.kernel.org;
> michael@walle.cc; palmer@dabbelt.com; linux-riscv@lists.infradead.org;
> alsa-devel@alsa-project.org; patches@opensource.cirrus.com; linuxppc-
> dev@lists.ozlabs.org; amitrkcian2002@gmail.com
> Subject: Re: [PATCH V6 09/15] spi: Add stacked and parallel memories
> support in SPI core
> 
> Hi,
> 
> On Fri, 10 Mar 2023 at 18:37, Amit Kumar Mahapatra <amit.kumar-
> mahapatra@amd.com> wrote:
> >
> > For supporting multiple CS the SPI device need to be aware of all the
> > CS values. So, the "chip_select" member in the spi_device structure is
> > now an array that holds all the CS values.
> >
> > spi_device structure now has a "cs_index_mask" member. This acts as an
> > index to the chip_select array. If nth bit of spi->cs_index_mask is
> > set then the driver would assert spi->chip_select[n].
> >
> > In parallel mode all the chip selects are asserted/de-asserted
> > simultaneously and each byte of data is stored in both devices, the
> > even bits in one, the odd bits in the other. The split is
> > automatically handled by the GQSPI controller. The GQSPI controller
> > supports a maximum of two flashes connected in parallel mode. A
> > "multi-cs-cap" flag is added in the spi controntroller data, through
> > ctlr->multi-cs-cap the spi core will make sure that the controller is
> > capable of handling multiple chip selects at once.
> >
> > For supporting multiple CS via GPIO the cs_gpiod member of the
> > spi_device structure is now an array that holds the gpio descriptor
> > for each chipselect.
> >
> > Multi CS support using GPIO is not tested due to unavailability of
> > necessary hardware setup.
> 
> Can you pinmux your SPI controller's (cs) pins as GPIO? If so, you should be
> able use that for testing.
> 

Xilinx Controller drivers that support multi cs are registered under 
spi-mem framework. So even if I modify the pinmux the chip selection 
will not go through the SPI core. 
So, we cannot test the CS GPIO changes in SPI core on our platforms.

> >
> > Signed-off-by: Amit Kumar Mahapatra <amit.kumar-
> mahapatra@amd.com>
> > ---
> >  drivers/spi/spi.c       | 225 +++++++++++++++++++++++++++-------------
> >  include/linux/spi/spi.h |  34 ++++--
> >  2 files changed, 182 insertions(+), 77 deletions(-)
> >
> > diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index
> > c725b4bab7af..742bd688381c 100644
> > --- a/drivers/spi/spi.c
> > +++ b/drivers/spi/spi.c
> > @@ -612,10 +612,17 @@ static int spi_dev_check(struct device *dev,
> > void *data)  {
> >         struct spi_device *spi = to_spi_device(dev);
> >         struct spi_device *new_spi = data;
> > -
> > -       if (spi->controller == new_spi->controller &&
> > -           spi_get_chipselect(spi, 0) == spi_get_chipselect(new_spi, 0))
> > -               return -EBUSY;
> > +       int idx, nw_idx;
> > +
> > +       if (spi->controller == new_spi->controller) {
> > +               for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) {
> > +                       for (nw_idx = 0; nw_idx < SPI_CS_CNT_MAX; nw_idx++) {
> > +                               if (spi_get_chipselect(spi, idx) ==
> > +                                   spi_get_chipselect(new_spi, nw_idx))
> > +                                       return -EBUSY;
> > +                       }
> > +               }
> 
> AFAICT unused chip selects are initialized to 0, so all single chip select devices
> would have it as their second one. This will then cause this check to reject
> every single chip select device after the first one. So you first need to make
> sure to only compare valid chip selects.
> 
> So the loop condition should be something along idx <
> spi_get_num_chipselect(), not idx < SPI_CS_CNT_MAX.
> 

Agreed, will update the loop condition as per num_cs.

> > +       }
> >         return 0;
> >  }
> >
> > @@ -629,7 +636,7 @@ static int __spi_add_device(struct spi_device
> > *spi)  {
> >         struct spi_controller *ctlr = spi->controller;
> >         struct device *dev = ctlr->dev.parent;
> > -       int status;
> > +       int status, idx;
> >
> >         /*
> >          * We need to make sure there's no other device with this @@
> > -638,8 +645,7 @@ static int __spi_add_device(struct spi_device *spi)
> >          */
> >         status = bus_for_each_dev(&spi_bus_type, NULL, spi, spi_dev_check);
> >         if (status) {
> > -               dev_err(dev, "chipselect %d already in use\n",
> > -                               spi_get_chipselect(spi, 0));
> > +               dev_err(dev, "chipselect %d already in use\n",
> > + spi_get_chipselect(spi, 0));
> 
> The message might be misleading for multi cs devices where the first one is
> free, but the second one is already in use.
> 
> So maybe move this error message into spi_dev_check(), where you have
> that information available. You then even have the chance to state what is
> using the CS then, but that might be something for a different patch.
> 
> 

Agreed, I will move the error message to spi_dev_check().

> >                 return status;
> >         }
> >
> > @@ -649,8 +655,10 @@ static int __spi_add_device(struct spi_device *spi)
> >                 return -ENODEV;
> >         }
> >
> > -       if (ctlr->cs_gpiods)
> > -               spi_set_csgpiod(spi, 0, ctlr->cs_gpiods[spi_get_chipselect(spi, 0)]);
> > +       if (ctlr->cs_gpiods) {
> > +               for (idx = 0; idx < SPI_CS_CNT_MAX; idx++)
> > +                       spi_set_csgpiod(spi, idx, ctlr-
> >cs_gpiods[spi_get_chipselect(spi, idx)]);
> > +       }
> >
> >         /*
> >          * Drivers may modify this initial i/o setup, but will @@
> > -690,13 +698,15 @@ int spi_add_device(struct spi_device *spi)  {
> >         struct spi_controller *ctlr = spi->controller;
> >         struct device *dev = ctlr->dev.parent;
> > -       int status;
> > +       int status, idx;
> >
> > -       /* Chipselects are numbered 0..max; validate. */
> > -       if (spi_get_chipselect(spi, 0) >= ctlr->num_chipselect) {
> > -               dev_err(dev, "cs%d >= max %d\n", spi_get_chipselect(spi, 0),
> > -                       ctlr->num_chipselect);
> > -               return -EINVAL;
> > +       for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) {
> > +               /* Chipselects are numbered 0..max; validate. */
> > +               if (spi_get_chipselect(spi, idx) >= ctlr->num_chipselect) {
> > +                       dev_err(dev, "cs%d >= max %d\n", spi_get_chipselect(spi,
> idx),
> > +                               ctlr->num_chipselect);
> > +                       return -EINVAL;
> > +               }
> >         }
> >
> >         /* Set the bus ID string */
> > @@ -713,12 +723,15 @@ static int spi_add_device_locked(struct
> > spi_device *spi)  {
> >         struct spi_controller *ctlr = spi->controller;
> >         struct device *dev = ctlr->dev.parent;
> > +       int idx;
> >
> > -       /* Chipselects are numbered 0..max; validate. */
> > -       if (spi_get_chipselect(spi, 0) >= ctlr->num_chipselect) {
> > -               dev_err(dev, "cs%d >= max %d\n", spi_get_chipselect(spi, 0),
> > -                       ctlr->num_chipselect);
> > -               return -EINVAL;
> > +       for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) {
> > +               /* Chipselects are numbered 0..max; validate. */
> > +               if (spi_get_chipselect(spi, idx) >= ctlr->num_chipselect) {
> > +                       dev_err(dev, "cs%d >= max %d\n", spi_get_chipselect(spi,
> idx),
> > +                               ctlr->num_chipselect);
> > +                       return -EINVAL;
> > +               }
> >         }
> >
> >         /* Set the bus ID string */
> > @@ -966,58 +979,119 @@ static void spi_res_release(struct
> > spi_controller *ctlr, struct spi_message *mes  static void
> > spi_set_cs(struct spi_device *spi, bool enable, bool force)  {
> >         bool activate = enable;
> > +       u32 cs_num = __ffs(spi->cs_index_mask);
> > +       int idx;
> >
> >         /*
> > -        * Avoid calling into the driver (or doing delays) if the chip select
> > -        * isn't actually changing from the last time this was called.
> > +        * In parallel mode all the chip selects are asserted/de-asserted
> > +        * at once
> >          */
> > -       if (!force && ((enable && spi->controller->last_cs ==
> spi_get_chipselect(spi, 0)) ||
> > -                      (!enable && spi->controller->last_cs != spi_get_chipselect(spi,
> 0))) &&
> > -           (spi->controller->last_cs_mode_high == (spi->mode &
> SPI_CS_HIGH)))
> > -               return;
> > -
> > -       trace_spi_set_cs(spi, activate);
> > -
> > -       spi->controller->last_cs = enable ? spi_get_chipselect(spi, 0) : -1;
> > -       spi->controller->last_cs_mode_high = spi->mode & SPI_CS_HIGH;
> > -
> > -       if ((spi_get_csgpiod(spi, 0) || !spi->controller->set_cs_timing) &&
> !activate)
> > -               spi_delay_exec(&spi->cs_hold, NULL);
> > -
> > -       if (spi->mode & SPI_CS_HIGH)
> > -               enable = !enable;
> > +       if ((spi->cs_index_mask & SPI_PARALLEL_CS_MASK) ==
> SPI_PARALLEL_CS_MASK) {
> > +               spi->controller->last_cs_mode_high = spi->mode &
> > + SPI_CS_HIGH;
> > +
> > +               if ((spi_get_csgpiod(spi, 0) || !spi->controller->set_cs_timing) &&
> !activate)
> > +                       spi_delay_exec(&spi->cs_hold, NULL);
> > +
> > +               if (spi->mode & SPI_CS_HIGH)
> > +                       enable = !enable;
> > +
> > +               if (spi_get_csgpiod(spi, 0) && spi_get_csgpiod(spi, 1)) {
> > +                       if (!(spi->mode & SPI_NO_CS)) {
> > +                               /*
> > +                                * Historically ACPI has no means of the GPIO polarity
> and
> > +                                * thus the SPISerialBus() resource defines it on the per-
> chip
> > +                                * basis. In order to avoid a chain of negations, the GPIO
> > +                                * polarity is considered being Active High. Even for the
> cases
> > +                                * when _DSD() is involved (in the updated versions of
> ACPI)
> > +                                * the GPIO CS polarity must be defined Active High to
> avoid
> > +                                * ambiguity. That's why we use enable, that takes
> SPI_CS_HIGH
> > +                                * into account.
> > +                                */
> > +                               if (has_acpi_companion(&spi->dev)) {
> > +                                       for (idx = 0; idx < SPI_CS_CNT_MAX; idx++)
> > +                                               gpiod_set_value_cansleep(spi_get_csgpiod(spi,
> idx),
> > +                                                                        !enable);
> > +                               } else {
> > +                                       for (idx = 0; idx < SPI_CS_CNT_MAX; idx++)
> > +                                               /* Polarity handled by GPIO library */
> > +                                               gpiod_set_value_cansleep(spi_get_csgpiod(spi,
> idx),
> > +                                                                        activate);
> > +                               }
> > +                       }
> > +                       /* Some SPI masters need both GPIO CS & slave_select */
> > +                       if ((spi->controller->flags & SPI_MASTER_GPIO_SS) &&
> > +                           spi->controller->set_cs)
> > +                               spi->controller->set_cs(spi, !enable);
> 
> > +                       else if (spi->controller->set_cs)
> > +                               spi->controller->set_cs(spi, !enable);
> 
> this else if belongs to the following brace as the else of the if
> (spi_get_csgpiod(spi, 0) && spi_get_csgpiod(spi, 1). Currently it would make

Agreed, will fix it in the next series.

> the first check redundant, as the second case would always be true if the first
> one is.
> 
> Actually shouldn't you iterate over the cs's here in case one is using
> set_cs() and the other one is gpiod? You can only get here if both are backed
> by gpiods. And you would only set the first cs, but not the second one. The -
> >set_cs() callback doesn't allow specifying which of the (multiple) cs's should
> be set though.
>
 
After fixing the else if indentation we will get here if either one of the
 CS support gpiod or both the CS support set_cs. Yes, one is using set_cs() 
and the other one is gpiod use case handling is missing. I need to iterate 
over the CS’s to find the CS GPIO, call gpiod_set_value_cansleep ( ) and 
then call set_cs( ). In the set_cs( ) driver API the driver needs to first check 
if any of the cs_index_mask enabled CS's is not a CS GPIO and then enable 
only the non-gpio CS. 
Please let me your thoughts on this approach.

> > +               }
> >
> > -       if (spi_get_csgpiod(spi, 0)) {
> > -               if (!(spi->mode & SPI_NO_CS)) {
> > -                       /*
> > -                        * Historically ACPI has no means of the GPIO polarity and
> > -                        * thus the SPISerialBus() resource defines it on the per-chip
> > -                        * basis. In order to avoid a chain of negations, the GPIO
> > -                        * polarity is considered being Active High. Even for the cases
> > -                        * when _DSD() is involved (in the updated versions of ACPI)
> > -                        * the GPIO CS polarity must be defined Active High to avoid
> > -                        * ambiguity. That's why we use enable, that takes
> SPI_CS_HIGH
> > -                        * into account.
> > -                        */
> > -                       if (has_acpi_companion(&spi->dev))
> > -                               gpiod_set_value_cansleep(spi_get_csgpiod(spi, 0),
> !enable);
> > -                       else
> > -                               /* Polarity handled by GPIO library */
> > -                               gpiod_set_value_cansleep(spi_get_csgpiod(spi, 0),
> activate);
> > +               for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) {
> > +                       if (spi_get_csgpiod(spi, idx) || !spi->controller-
> >set_cs_timing) {
> > +                               if (activate)
> > +                                       spi_delay_exec(&spi->cs_setup, NULL);
> > +                               else
> > +                                       spi_delay_exec(&spi->cs_inactive, NULL);
> > +                       }
> 
> Won't you delay twice if both CS's are backed by gpiod (and the controller
> does not implement set_cs_timing)? You should probably break after the
> first or so.
> 

True, I will add a check to avoid extra delay.

> I wonder if it would makes sense to have a helper function to set cs state to
> all cs's indicated by cs_index_mask so you can share most of the logic
> between the single and multi cs paths.
> 
> Currently it seems both paths have a lot of code (and comment) duplication,
> with the difference being one path is touching one cs and the other two (or
> all).
> 

Agreed, will update the logic.

> >                 }
> > -               /* Some SPI masters need both GPIO CS & slave_select */
> > -               if ((spi->controller->flags & SPI_MASTER_GPIO_SS) &&
> > -                   spi->controller->set_cs)
> > +       } else {
> > +               /*
> > +                * Avoid calling into the driver (or doing delays) if the chip select
> > +                * isn't actually changing from the last time this was called.
> > +                */
> > +               if (!force && ((enable && spi->controller->last_cs ==
> > +                               spi_get_chipselect(spi, cs_num)) ||
> > +                               (!enable && spi->controller->last_cs !=
> > +                                spi_get_chipselect(spi, cs_num))) &&
> > +                   (spi->controller->last_cs_mode_high ==
> > +                    (spi->mode & SPI_CS_HIGH)))
> > +                       return;
> > +
> > +               trace_spi_set_cs(spi, activate);
> > +
> > +               spi->controller->last_cs = enable ? spi_get_chipselect(spi, cs_num)
> : -1;
> > +               spi->controller->last_cs_mode_high = spi->mode &
> > + SPI_CS_HIGH;
> > +
> > +               if ((spi_get_csgpiod(spi, cs_num) || !spi->controller-
> >set_cs_timing) && !activate)
> > +                       spi_delay_exec(&spi->cs_hold, NULL);
> > +
> > +               if (spi->mode & SPI_CS_HIGH)
> > +                       enable = !enable;
> > +
> > +               if (spi_get_csgpiod(spi, cs_num)) {
> > +                       if (!(spi->mode & SPI_NO_CS)) {
> > +                               /*
> > +                                * Historically ACPI has no means of the GPIO polarity
> and
> > +                                * thus the SPISerialBus() resource defines it on the per-
> chip
> > +                                * basis. In order to avoid a chain of negations, the GPIO
> > +                                * polarity is considered being Active High. Even for the
> cases
> > +                                * when _DSD() is involved (in the updated versions of
> ACPI)
> > +                                * the GPIO CS polarity must be defined Active High to
> avoid
> > +                                * ambiguity. That's why we use enable, that takes
> SPI_CS_HIGH
> > +                                * into account.
> > +                                */
> > +                               if (has_acpi_companion(&spi->dev))
> > +                                       gpiod_set_value_cansleep(spi_get_csgpiod(spi,
> cs_num),
> > +                                                                !enable);
> > +                               else
> > +                                       /* Polarity handled by GPIO library */
> > +                                       gpiod_set_value_cansleep(spi_get_csgpiod(spi,
> cs_num),
> > +                                                                activate);
> > +                       }
> > +                       /* Some SPI masters need both GPIO CS & slave_select */
> > +                       if ((spi->controller->flags & SPI_MASTER_GPIO_SS) &&
> > +                           spi->controller->set_cs)
> > +                               spi->controller->set_cs(spi, !enable);
> > +               } else if (spi->controller->set_cs) {
> >                         spi->controller->set_cs(spi, !enable);
> > -       } else if (spi->controller->set_cs) {
> > -               spi->controller->set_cs(spi, !enable);
> > -       }
> > +               }
> >
> > -       if (spi_get_csgpiod(spi, 0) || !spi->controller->set_cs_timing) {
> > -               if (activate)
> > -                       spi_delay_exec(&spi->cs_setup, NULL);
> > -               else
> > -                       spi_delay_exec(&spi->cs_inactive, NULL);
> > +               if (spi_get_csgpiod(spi, cs_num) || !spi->controller-
> >set_cs_timing) {
> > +                       if (activate)
> > +                               spi_delay_exec(&spi->cs_setup, NULL);
> > +                       else
> > +                               spi_delay_exec(&spi->cs_inactive, NULL);
> > +               }
> >         }
> >  }
> >
> > @@ -2246,8 +2320,8 @@ static void of_spi_parse_dt_cs_delay(struct
> > device_node *nc,  static int of_spi_parse_dt(struct spi_controller *ctlr,
> struct spi_device *spi,
> >                            struct device_node *nc)  {
> > -       u32 value;
> > -       int rc;
> > +       u32 value, cs[SPI_CS_CNT_MAX] = {0};
> > +       int rc, idx;
> >
> >         /* Mode (clock phase/polarity/etc.) */
> >         if (of_property_read_bool(nc, "spi-cpha")) @@ -2320,13
> > +2394,21 @@ static int of_spi_parse_dt(struct spi_controller *ctlr, struct
> spi_device *spi,
> >         }
> >
> >         /* Device address */
> > -       rc = of_property_read_u32(nc, "reg", &value);
> > -       if (rc) {
> > +       rc = of_property_read_variable_u32_array(nc, "reg", &cs[0], 1,
> > +                                                SPI_CS_CNT_MAX);
> > +       if (rc < 0 || rc > ctlr->num_chipselect) {
> >                 dev_err(&ctlr->dev, "%pOF has no valid 'reg' property (%d)\n",
> >                         nc, rc);
> >                 return rc;
> > +       } else if ((of_property_read_bool(nc, "parallel-memories")) &&
> > +                  (!ctlr->multi_cs_cap)) {
> > +               dev_err(&ctlr->dev, "SPI controller doesn't support multi CS\n");
> > +               return -EINVAL;
> >         }
> > -       spi_set_chipselect(spi, 0, value);
> > +       for (idx = 0; idx < rc; idx++)
> > +               spi_set_chipselect(spi, idx, cs[idx]);
> > +       /* By default set the spi->cs_index_mask as 1 */
> > +       spi->cs_index_mask = 0x01;
> >
> >         /* Device speed */
> >         if (!of_property_read_u32(nc, "spi-max-frequency", &value)) @@
> > -3846,6 +3928,7 @@ static int __spi_validate(struct spi_device *spi, struct
> spi_message *message)
> >         struct spi_controller *ctlr = spi->controller;
> >         struct spi_transfer *xfer;
> >         int w_size;
> > +       u32 cs_num = __ffs(spi->cs_index_mask);
> >
> >         if (list_empty(&message->transfers))
> >                 return -EINVAL;
> > @@ -3858,7 +3941,7 @@ static int __spi_validate(struct spi_device *spi,
> struct spi_message *message)
> >          * cs_change is set for each transfer.
> >          */
> >         if ((spi->mode & SPI_CS_WORD) && (!(ctlr->mode_bits &
> SPI_CS_WORD) ||
> > -                                         spi_get_csgpiod(spi, 0))) {
> > +                                         spi_get_csgpiod(spi,
> > + cs_num))) {
> 
> Wouldn't you need to check for any of the cs_index_mask enabled CS's, and
> not just the first one? AFAICT you would currently fail to catch a
> SPI_CS_WORD transfer with both cs enabled where the first one is a
> SPI_CS_WORD capable native CS and the second one a gpiod.
> 

That’s true, I will add a loop and check for each of the cs_index_mask 
enabled CS's.

> >                 size_t maxsize;
> >                 int ret;
> >
> > diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h index
> > bdb35a91b4bf..452682aa1a39 100644
> > --- a/include/linux/spi/spi.h
> > +++ b/include/linux/spi/spi.h
> > @@ -19,6 +19,11 @@
> >  #include <linux/acpi.h>
> >  #include <linux/u64_stats_sync.h>
> >
> > +/* Max no. of CS supported per spi device */ #define SPI_CS_CNT_MAX 2
> > +
> > +/* chip select mask */
> > +#define SPI_PARALLEL_CS_MASK   (BIT(0) | BIT(1))
> >  struct dma_chan;
> >  struct software_node;
> >  struct ptp_system_timestamp;
> > @@ -166,6 +171,7 @@ extern void
> spi_transfer_cs_change_delay_exec(struct spi_message *msg,
> >   *     deasserted. If @cs_change_delay is used from @spi_transfer, then
> the
> >   *     two delays will be added up.
> >   * @pcpu_statistics: statistics for the spi_device
> > + * @cs_index_mask: Bit mask of the active chipselect(s) in the
> > + chipselect array
> >   *
> >   * A @spi_device is used to interchange data between an SPI slave
> >   * (usually a discrete chip) and CPU memory.
> > @@ -181,7 +187,7 @@ struct spi_device {
> >         struct spi_controller   *controller;
> >         struct spi_controller   *master;        /* Compatibility layer */
> >         u32                     max_speed_hz;
> > -       u8                      chip_select;
> > +       u8                      chip_select[SPI_CS_CNT_MAX];
> >         u8                      bits_per_word;
> >         bool                    rt;
> >  #define SPI_NO_TX      BIT(31)         /* No transmit wire */
> > @@ -202,7 +208,7 @@ struct spi_device {
> >         void                    *controller_data;
> >         char                    modalias[SPI_NAME_SIZE];
> >         const char              *driver_override;
> > -       struct gpio_desc        *cs_gpiod;      /* Chip select gpio desc */
> > +       struct gpio_desc        *cs_gpiod[SPI_CS_CNT_MAX];      /* Chip select
> gpio desc */
> >         struct spi_delay        word_delay; /* Inter-word delay */
> >         /* CS delays */
> >         struct spi_delay        cs_setup;
> > @@ -212,6 +218,13 @@ struct spi_device {
> >         /* The statistics */
> >         struct spi_statistics __percpu  *pcpu_statistics;
> >
> > +       /* Bit mask of the chipselect(s) that the driver need to use from
> > +        * the chipselect array.When the controller is capable to handle
> > +        * multiple chip selects & memories are connected in parallel
> > +        * then more than one bit need to be set in cs_index_mask.
> > +        */
> > +       u32                     cs_index_mask : 2;
> 
> SPI_CS_CNT_MAX?
> 

Agreed, will replace 2 with SPI_CS_CNT_MAX.

> > +
> >         /*
> >          * likely need more hooks for more protocol options affecting how
> >          * the controller talks to each chip, like:
> > @@ -268,22 +281,22 @@ static inline void *spi_get_drvdata(struct
> > spi_device *spi)
> >
> >  static inline u8 spi_get_chipselect(struct spi_device *spi, u8 idx)
> > {
> > -       return spi->chip_select;
> > +       return spi->chip_select[idx];
> >  }
> >
> >  static inline void spi_set_chipselect(struct spi_device *spi, u8 idx,
> > u8 chipselect)  {
> > -       spi->chip_select = chipselect;
> > +       spi->chip_select[idx] = chipselect;
> >  }
> >
> >  static inline struct gpio_desc *spi_get_csgpiod(struct spi_device
> > *spi, u8 idx)  {
> > -       return spi->cs_gpiod;
> > +       return spi->cs_gpiod[idx];
> >  }
> >
> >  static inline void spi_set_csgpiod(struct spi_device *spi, u8 idx,
> > struct gpio_desc *csgpiod)  {
> > -       spi->cs_gpiod = csgpiod;
> > +       spi->cs_gpiod[idx] = csgpiod;
> >  }
> >
> >  /**
> > @@ -388,6 +401,8 @@ extern struct spi_device
> *spi_new_ancillary_device(struct spi_device *spi, u8 ch
> >   * @bus_lock_spinlock: spinlock for SPI bus locking
> >   * @bus_lock_mutex: mutex for exclusion of multiple callers
> >   * @bus_lock_flag: indicates that the SPI bus is locked for exclusive
> > use
> > + * @multi_cs_cap: indicates that the SPI Controller can assert/de-assert
> > + *     more than one chip select at once.
> >   * @setup: updates the device mode and clocking records used by a
> >   *     device's SPI controller; protocol code may call this.  This
> >   *     must fail if an unrecognized or unsupported mode is requested.
> > @@ -585,6 +600,13 @@ struct spi_controller {
> >         /* Flag indicating that the SPI bus is locked for exclusive use */
> >         bool                    bus_lock_flag;
> >
> > +       /*
> > +        * Flag indicating that the spi-controller has multi chip select
> > +        * capability and can assert/de-assert more than one chip select
> > +        * at once.
> > +        */
> > +       bool                    multi_cs_cap;
> 
> I admit I haven't followed the first iterations, but Is there a reason this isn't a
> SPI_XXX flag in spi.h? There seem to be quite a few free bits left.
> 

Yes, it can be a SPI_XX flag as well. I will add a flag & remove this 
structure member.

> I would think multi_cs can be emulated (somewhat) via gpiod for the second
> CS as long as the controller supports set_cs() (and SPI_NO_CS?).
> 

It is not just about handling the CS's, but rather this flag indicates 
that the controller can communicate (reading & writing data) with 
both the devices simultaneously.

Regards,
Amit

> > +
> >         /* Setup mode and clock, etc (spi driver may call many times).
> >          *
> >          * IMPORTANT:  this may be called when transfers to another
> > --
> > 2.25.1
> >
> 
> Regards
> Jonas